Standard Deck Bowtie Sportsman Block

2-Piece Rear Main Seal
Big Blocks with big power are what you get when you select a Chevrolet Performance Bowtie Sportsman block for your drag racing or extreme street-performance application. These blocks comprise a full line of high-quality, precision-machined components based on performance-proven GM designs. The extensive lineup of blocks makes choosing the perfect block easy – and our quality and precision machining is second to none.
The blocks are CNC-machined, an automated process that guarantees precise tolerances. There are no approximations on these blocks–they’re exactly right, which is critical to obtaining maximum performance. Chevrolet Performance offers more CNC-machined blocks than anyone.
The highest-quality materials are used to cast our Sportsman Bowtie blocks. They are also available as tall decks, allowing you to make more cubic inches with larger-stroke crankshafts. These blocks can easily be bored and stroked to 500-or-more cubic inches. They can be fitted with one-piece or two-piece crankshaft seals for a smaller chance of oil leaks (one-piece seals) or more aftermarket components attachments (two-piece seals).
The Bowtie Sportsman blocks are available with splayed main caps, which have additional material holding the crankshaft in place. The caps are splayed at 16 degrees. Chevrolet Performance uses splayed main caps throughout the entire line of performance-built Big Blocks.
Chevrolet Performance Bowtie Sportsman Blocks are ideal for drag racers or street machines where the goal is 800 horsepower and long-lasting reliability.
19212191 Chevrolet Sportsman Block
2-piece rear main seal
CNC-machined cast iron 4-bolt block
4.494″ finished bore
4.600″ max bore
Tested to 800 horsepower!
Bowtie Sportsman Block Technical Notes:
Available in short deck (9.800″) or tall deck (10.200″)configurations
Blocks have clearance for 4.500″ stroke crankshafts
CNC-machined to +/- .001″ tolerance
Siamese cylinder bores
Bore finishes are ready to hone to size
Machined for mechanical fuel pump
Machined for hydraulic roller and flat tappets
Nodular iron 4-bolt main caps splayed 16° on the three center mains
Priority main oiling system
Blocks with a 1-piece Rear Main Seal use the 6-bolt, GenVI-style front cover (P/N 10230954) and Gen VI-style oil pan
Blocks with a 2-piece Rear Main Seal use the 10-bolt, Mark IV-style front cover and Mark IV-style oil pan