12480175 - Bowtie Sportsman Chevy Small Block - 4.117"-4.155" Bore, 9.025" Deck, 2.45" Mains, 4 Bolt Main, Siamesed Bores

This is the block to buy if you want to build a serious street car or if you want to head to the race track! The GM performance parts Bowtie Sportsman block has been the starting point for numerous racing engines. These blocks have siamesed cylinder walls and four bolt main caps secured by grade 8 bolts. All blocks in this family have a 9.025" deck height. The Bowtie Sportsman blocks are a great foundation for your serious street car, circle track or drag race car that makes between 350 and 500 horsepower.

350 Main, 400 Bore Size Bowtie Sportsman Block, 1 Piece rear main seal

• CNC machined cast-iron competition block
• +/- .001 machining tolerance
• 4 bolt nodular mains, splayed caps on center 3 mains
• 4.117" finished bore
• 4.155" max bore
• Extra smooth gasket surfaces for better sealing
• Tall lifter bores
• Oil dipstick holes are not drilled
• Timing system clearance must be checked
• Seal adapter 10051118 required to use 2-piece rear main crankshafts in a 1-piece rear main block.