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Small Block Chevy V8 Blocks

10051181
Cast Iron Bow Tie Bare Block
$1784

The Bow Tie block's oil galleries now extend to the front and rear faces of the cylinder case. The ends of the galleries are machined flat, providing a smooth starting surface for the drill bits that bore the oil holes from the front and rear of the block. These extended front galleries can interfere with some camshaft drive systems; therefore, the clearance should be checked before engine assembly. The revised Bow Tie block has a boss below the bellhousing flange behind the #8 cylinder that can be drilled and tapped for a lifter valley oil scavenge line. Oil drainback holes in the lifter valley are now drilled instead of cast. Locating pads in the valley have been revised to accommodate the new tooling; although the pads differ from previous designs, they do not affect the block's functionality. The updated design provides more consistency in the thickness of the cylinder walls and water jackets.  
Technical Notes: The small-bore Bow Tie block casting P/N 10051182 is identical to the big-bore except for its cylinder diameter and water jackets. It has finish machined lifter bores with production size .842" and 2-bolt main bearing caps. This block is machined for a one-piece rear main seal; use crankshaft seal adapter P/N 10051118 when installing a crankshaft designed for a two-piece seal.

10051183
Cast Iron Bow Tie Bare Block (3.98" bore)
$1994

This updated design has a decidedly different appearance, but retains its original part number. New tooling procedures have significantly improved the quality and dura-bility of this third-generation casting. This heavy-duty cast iron Bow Tie block has rough-bored 3.98" diameter cylinders, which can be bored to a maximum diameter of 4.090". This block is recommended for maximum effort competition engines. The deck surfaces are thicker than production blocks, and the head bolt holes are blind tapped to improve head gasket sealing. The main bearing bulkheads are .900" thick and the front and rear bulkheads are reinforced with strengthening ribs. The updated design on this Bow Tie block's oil galleries now extend to the front and rear faces of the cylinder case. The ends of the galleries are machined flat, providing a smooth starting surface for the drill bits that bore the oil holes from the front and rear of the block. These extended front galleries can interfere with some camshaft drive systems; therefore, the clearance should be checked before engine assembly. The revised Bow Tie block has a boss below the bellhousing flange behind the #8 cylinder that can be drilled and tapped for a lifter valley oil scavenge line. Bosses were also added to the outer water jacket walls to allow coolant passages to be drilled between adjacent cylinders which have siamesed cylinder walls. Oil drainback holes in the lifter valley are now drilled instead of cast. Locating pads in the valley have been revised to accommodate the new tooling; although the pads differ from previous designs, they do not affect the block's functionality. The updated design provides more consistency in the thickness of the cylinder walls and water jackets. The siamesed bore have a nominal cylinder wall thickness of .340" at the casting parting line (measured 2" below the deck surface).  
Technical Notes: Oil dipstick hole is not drilled and the lifter holes are finish bored to production diameter .842". 2-bolt main bearing caps are installed to simplify the installation of the heavy-duty steel main caps with splayed outer bolts. Bow Tie blocks are designed for crankshafts with 2.45" diameter main bearing journals. The Bow Tie casting block P/N 10051184 is machined for a one-piece rear main bearing seal used on 1986 and later production small- block Chevrolet V8s. Crankshafts designed for two-piece rear main seals can be installed in Bow Tie blocks using crankshaft seal adapter P/N 10051118. These blocks weigh 181 lbs.

10066034
350ci Bare Block
$759

This 350ci iron bare block is used on the 1973-85 GM Goodwrench 350 engine and has the early-style 2-piece rear main seal. Its main bearing caps are the straight type four-bolt design. The block has a standard 4.00" cylinder bore.  
Technical Notes: Can be used for 302, 327 and 350 engines. (Does not include oil galley plugs or dowel pins.)

10066098
305ci Bare Block
$744

This production cast iron cylinder case has 3.74" diameter cylinder bores and two-bolt main bearing caps. It uses a one-piece rear crankshaft seal. 1986 and newer.  
Technical Notes: This block's cylinder walls are the same thickness as current production engines. Its lifter valley is machined for hydraulic roller and flat tappets. Crankshafts with two-piece seals can be installed with adapter P/N 10051118.

10105123
350ci Bare Block
$759

This engine block is used in 1986-99 Gen I heavy-duty applications. It has 4.00" diameter cylinder bores and four-bolt main bearing caps. This block is machined for a one-piece rear crankshaft seal. (Does not include rear seal or adaptor.) These blocks weigh 197 lbs.  
Technical Notes: Cylinder wall thickness is the same as current production engines. The lifter valley is machined for hydraulic roller and flat tappets. Crankshafts with two-piece seals can be installed with adapter P/N 10051118. (Block casting P/N 10243880 or 14093638.)

10134400
Aluminum V8 Block
$4724

This block has the same dimensions and characteristics of the Aluminum Cylinder Case (P/N 10185075) except that it has a 2.65" (400ci) diameter main bearing size and the bore is 4.120". Use cam bearing kit P/N 12370843. This block is machined for a dry sump oiling system.  
 

10185047
350ci Bow Tie Block
$2204

This block, which can be used for 302ci, 327ci, and 350ci engines, is the same as the cast iron Bow Tie bare block P/N 10051183, except that it has a "straight" nodular 4-bolt main bearing cap. It also features "siamesed" cylinder walls which could give it a maximum bore of 4.150". It has a crankshaft diameter of 2.45" and the newer (1986 and later) one-piece type rear main seal. It replaces the older P/N 366287 4-bolt block, the difference being the one-piece rear seal rather than older 2-piece rear main seal. Block weight is 182 lbs.  
 

10185075
Aluminum V8 Cylinder Case
$4724

This aluminum V8 bare block weighs 90 lbs. and is cast from prime ingot A-356 aluminum with heat treatment to T6 specification. Wall thicknesses have been increased for greater stress capabilities. The main bearing diameter is 2.45". Its rigid deck surfaces are .620". It has blind-tapped head bolt holes to improve head gasket sealing. The cylinder sleeves are semi-finished at 3.986" and will finish at 4.150" bore diameter. It has a 4-bolt main bearing cap on all five locations of 8620 steel which will clear standard oil pans. The rear main bearing is the 2-piece, pre-1986 design. These blocks are wet sump designed but can be converted to dry sump oiling by simply plugging the oil pump hole in its rear main bearing cap.  
Technical Notes: Use cam bearing kit P/N 12370843.

12480030
Cylinder Block, "Gen 3" V8 (LS1)
$
The "Gen 3" V8 (RPO-LS1) engine is used in all 1997 and later Corvettes, and 1998 and later Camaros. Use with special cylinder head P/N 12480005. To compete successfully in GT-2 racing an aftermarket parts development started with the intent of providing the new GM powertrain LS1 engine a higher performance platform. One of the first components designed was the cylinder and case with an intent to provide a part that was similar to the LS1 in appearance for sanctioning body approval. The cylinder and case includes the following features: Production pattern equipment used for all external features and "V" barrel cores. The water jacket retains the outer shape and length features with a revised inside diameter to provide the material necessary for a larger outside diameter cylinder bore liner. Production A319 material with a modified T7 heat treatment. All stock attachment surfaces have been maintained. All stock attachment and metric fasteners have been maintained. The bore liner is a pressed fit design similar to the current aluminum V8 parts available from GM SPO. The powered metal main caps have been replaced with steel billet parts. A-1 products has provided the metric to English stud kits. Currently the final racing configuration has to be finalized versus the commercially available part for GM SPO.  
 

12480045
Block, 350 NASCAR Busch Series "327" Crank
$4829
These 350 "CNC" blocks are designed for NASCAR series racing. They are light weight with the following specifications: CNC machined; 2.30" crankshaft diameter; 9.025 deck height; Bulk heads machined at 5 degrees; Special steel main caps; 6AN water drain; 45 degree -10 AN fitting front oil feed; 4 center valley drains drilled & tapped; Steam holes between cyl .0750 from deck; 4.115" bore diameter; 58mm roller cam bearings; .875 lifter bore diameter; AN o-ring plug replacement pipe plugs; 1/2" NPS water hole each side of block; and degree -10 AN fitting valley scavenge.  
 

12480046
Block, 350 NASCAR Busch Series "2.64" Crank"
$4829
These 350 "CNC" blocks are designed for NASCAR series racing. They are light weight with the following specifications: CNC machined; 2.64" crankshaft diameter; 9.025 deck height; Bulk heads machined at 5 degrees; Special steel main caps; 6AN water drain; 45 degree -10 AN fitting front oil feed; 4 center valley drains drilled & tapped; Steam holes between cyl .0750 from deck; 4.115" bore diameter; 2.28" camshaft diameter; .875 lifter bore diameter; AN o-ring plug replacement pipe plugs; 1/2" NPS water hole each side of block; 45 degree -10 AN fitting valley scavenge.  
 

12480047
Block, Bow-Tie Sportsman "350 Main Size"
$2098

This iron block is fully CNC machined from the H-D 10051184 casting. It has siamesed cylinder walls, cast nodular caps, four bolts on all five main caps; the outer bolts on the three center main caps are splayed 20 degrees. Grade 8 bolts secure the caps. It features priority main oiling and 9.025" deck height. The blocks come finished bored at 3.980" and the maximum recommended bore is 4.150". This block features a two-piece rear main seal; "350" main size (2.45"). It features lifter bore heights (.842"), same as P/N 24502503.  
Technical Notes: It may be necessary to clearance top of lifter bores with some roller lifters. The block requires 2" O.D. cam bearings at all five locations (P/N 12370843 set).

12480049
Block, Bow-Tie Sportsman "400 Main Size"
$1994

This iron block is fully CNC machined from the H-D 10051184 casting. It has siamesed cylinder walls, cast nodular caps, four bolts on all five main caps; the outer bolts on the three center main caps are splayed 20 degrees. Grade 8 bolts secure the caps. It features priority main oiling and 9.025" deck height. The blocks come finished bored at 3.980" and the maximum recommended bore is 4.150". This block features a two-piece rear main seal; "400" main size (2.65"). It features lifter bore heights (.842"), same as P/N 24502503.  
Technical Notes: It may be necessary to clearance top of lifter bores with some roller lifters. The block requires 2" O.D. cam bearings at all five locations (P/N 12370843 set).

22551788
Cast Iron Rocket Block (Standard w/Wet Sump)
$2729
This block is the same as P/N 22551790, except this is a standard type with a wet sump.

Part Number.....22551788............22551790
Deck Height......9.025"(std.).........9.325" (tall)
Oiling System...Wet Sump...........Wet Sump
Main Bearings...2.45" (350-type)...2.65" (400 type)
Bore Diameter...4.000"-4.190"......4.125"-4.190"  
 

22551790
Cast Iron Rocket Block (Tall w/Wet Sump)
$2729

This cast iron block is precision machined and does not require additional "blueprinting" to correct production tolerances. All block dimensions are machined to +/- .001". The block's extra-thick siamesed cylinder walls provide a minimum .275" wall thickness with a 4.125" bore. The cylinders can be bored to a maximum of 4.155" diameter. This block also uses the standard GM small-block V8's 4.400" cylinder bore centerlines. The outer water jacket walls are scalloped to enhance coolant flow around the siamesed cylinders. This block is available with deck height 9.325" (.300" taller than production). The reinforced deck has a minimum .625" deck thickness, regardless of the deck height specified. The head bolt holes are blind-tapped and the head bolt bosses are freestanding to minimize cylinder bore distortion. The three steel 4-bolt center main bearing caps have splayed outer bolts. The 2-bolt front and rear bearing caps are retained with studs. Blocks with standard deck heights use 2.45" main bearings; tall deck height blocks use 2.65" main bearings. This block uses a pre- 1985 two-piece small-block rear main bearing seal. Compared to a production small-block V8, the Rocket block's camshaft is raised .390" (4.912" camshaft-to-crankshaft centerlines). This relocated camshaft will clear a 4.125" stroke crankshaft without interference, eliminating the need for a small base circle cam when using a long-stroke crankshaft. This block uses big- block V8 cam bearings. These larger cam journals allow the camshaft base circle diameter to be enlarged, which enhances camshaft strength and reliability. The lubrication system has been revised. This block has a "priority main" lubricating system that directs oil to the main bearings before the cam bearings. The main oil gallery is located next to the camshaft tunnel: oil can be pumped into this gallery through a boss above the timing chain cover or through the bellhousing flange behind the #7 cylinder. In wet sump versions, the rear main bearing cap is machined for a standard oil pump. The oil pan rails are spread .800" (.400" per side) compared to a production small-block V8. These pan rails will clear up to a 4.125" stroke crankshaft in tall deck blocks with minor modifications. Other additions to this block are: dual starter mounts, production bosses for side and front engine mounts, and provisions for a block-mounted mechanical fuel pump.

Part Number.....22551788............22551790
Deck Height......9.025"(std.).........9.325" (tall)
Oiling System...Wet Sump...........Wet Sump
Main Bearings...2.45" (350-type)...2.65" (400 type)
Bore Diameter...4.000"-4.190"......4.125"-4.190"  
Technical Notes: Depending on components used, bottom of bores and oil pan rails may require notching and additional machine work for connecting rod and counterweight clearance. Mounting the starter on the left (driver's) side of the block provides additional clearance for an extended oil pan. If the block-mounted oil filter is eliminated, a remote filter is required.

24502495
Aluminum V8 Block for Big Displacement Engines
$5669

This tall deck (9.525") aluminum block can be bored to (4.160") and stroke to (4.125" with minor modification and 4.250" stroke with major modifications). The deck height is 9.525" with a 1.125" deck surface that can be machined as low as 9.000". The bores start at 4.119" and can be bored to 4.160" with a 2.65" (400-type) main bearing size and the camshaft is raised 0.391" from production location. Pan rails are spread 0.400" per side for clearance of connecting rods. The main caps are four-bolt design of 8620 steel with the three inner middle caps having ball-end outer studs that are angled outward at 20º to anchor the caps to the strongest part of the block. The four-bolt front and rear caps have straight outer bolts for oil pan clearance. The main cap hardware includes premium bolts, centerless ground studs and 12-point nuts. The rear main uses a 400-type two-piece rear seal (Fel-Pro P/N 2909). This block uses a priority main oiling system and is a dry sump design with no provisions for an internal oil pump. The oil filter pad is eliminated so the starter can be mounted on either side and the fuel pump boss is also removed.  
Technical Notes: Special oil pan, camshaft, and timing chain are required for this block. Use cam bearing kit P/N 12370843.

24502501
Small Bore Cast Iron V8 Racing Block
$3149

This Bow Tie bare block is intended for serious competition applications right out of the box. This block is "CNC" machined from a raw casting P/N 10051182. All traditional racing modifications are provided by the factory. The heart of this block starts with a non-siamesed cylinder case raw casting P/N 10051182 at a 3.875" bore, but can be bored to 4.030". This case is then blueprinted on the cylinder decks (9.025" deck height), front of case, rear of case, and oil pan rail surfaces as well as the head dowel locator pin locations. In addition, all galleries required for dry sump oil system operation are oversize and tapped for pipe plugs. 8620 steel bearing caps are installed on all locations on the block. The intermediate main bearing caps have the outer 7/16" diameter studs installed at a 20 degree splay, while the front bearing cap has 7/16" diameter studs on the inner locations and 3/8" diameter straight bolts on the outer locations. The rear bearing cap is a 2 stud (7/16" dia.) configuration and utilizes a two piece rear seal design adaptable to the one piece design. After installation of the steel bearing caps, the block is align bored. Use cam bearing kit P/N 12370843. They are 2.00" O.D. and 1.867" I.D.  
Technical Notes: The above bore sizes are after honing .005" from the cylinder by a professional engine builder. Special features are: Priority main oiling; Bearing cap inner bolts spread .210 to allow use of "2.65" dia. journal cranks on properly modified blocks; Sonic bore check (data provided); Enlarged cam bosses front and rear to allow use of larger bearings; Enlarged lifter bosses; Production .842" lifter bores; Early model two-piece rear main seals; Uses pre-1986 oil pans; Uses premium quality studs and 8620 20º steel splayed main bearing caps; and Billet wet sump rear main cap can be adapted to dry sump with plugs.

24502503
4.00" Bore Cast Iron Racing Bow Tie Bare Block
$3359

This block is "CNC" machined from a raw casting P/N 10051184. All traditional racing modifications are provided by the factory. The heart of this block starts with a siamesed bore cylinder case at a 3.995" bore, but can be bored to 4.155". This case is then blueprinted on the cylinder decks (9.025" deck height), front of case, rear of case, and oil pan rail surfaces as well as the head dowel locator pin locations. In addition all galleries required for dry sump oil system operation are drilled and tapped for pipe. 8620 steel bearing caps are installed on all locations on the block. The intermediate main bearing caps have the outer 7/16" diameter studs installed at a 20º splay, while the front bearing cap has 7/16" diameter studs on the inner locations and 3/8" diameter straight bolts on the outer locations. The rear bearing cap is a two- stud (7/16" dia.) configuration and utilizes a two-piece rear seal design. After installation of the steel bearing caps, the block is align bored. Use cam bearing kit P/N 12370843 only.  
Technical Notes: The above bore sizes are after honing .005" from the cylinder by a professional engine builder. Special features are: Priority main oiling; Bearing cap inner bolts spread .210 to allow use of "2.65" dia. journal cranks on properly modified blocks; Sonic bore check (data provided); Enlarged cam bosses front and rear to allow use of larger bearings; Enlarged lifter bosses; Early model two-piece rear main seals; Uses pre-1986 oil pans; and Uses premium quality studs and 8620 20º steel splayed main bearing caps.

24502525
Bow Tie CNC Racing Block Tall Deck
$3464
This is the same as racing bare block P/N 24502503 except is has higher deck height - 9.150, but can be machined to standard 9.025" deck height. It can be bored to 4.155".  
 

24502600
SB2 / SB2.2 Bare Block
$3359
This "CNC machined" bare block uses bow tie casting P/N 10051184 and is machined identically to block P/N 24502503 except the lifter bore locations have been revised to match the SB2 or SB2.2 cylinder head.  
Technical Notes: Production blocks can be used if offset roller rockers and roller tappets are used. Must use special camshaft when using SB2 or SB2.2 cylinder heads.

24502650
Bow Tie CNC Racing Block "Short Deck"
$3464

This "CNC machined" cast iron bow tie block has an 8.200" deck to crankshaft, compared to the standard block with a 9.025" deck. This block is designed for small cubic inch engines used in drag racing, road racing, or restricted oval track racing. The factory bore on this siamesed block is 3.894" "and can be bored to a maximum of 4.190"" with a minimum wall thickness of .250". The camshaft has been raised up 4.953" and the main oil gallery relocated from above the camshaft to the side of the cam. The water pump holes are spread and a big block water pump must be used. When a 6" or larger damper is used, the pump must be raised with aluminum adapters. With the shorter deck, the pushrods must be shorter and mate with the cam and lifters. The main bearing diameters are 2.30", not the standard 2.45". The cam bearing holes are bored for roller bearings at 2.250" diameter O.D. x 1.875" I.D. This block features five steel main caps with the three center caps splayed at 20º, and the block weight is approximately 167 lbs.  
Technical Notes: This block uses the Oldsmobile Aurora V8 design bell housing with a maximum of 12.25" diameter flywheel. These blocks also use early style two-piece rear oil seals with late model one-piece molded oil pan gaskets. The lifter bosses are .220" taller than production blocks. These blocks will accept all V8 cylinder heads. The oil filter boss is a machined pad for a remote oil filter adapter - or tap for a fitting. They uses a dry sump oil system only and have provisions for an integral lifter valley scavenge system. Oil is scavenged through a hole at the rear of the valley. This block does not have a manual fuel pump boss, but it features bosses for cylinder pressure transducers for development in testing.