Dart engineered the Big M to be the strongest, most reliable, and easiest to build big block on the market.
With deck height of 9.800” and bore size 4.250”, the Big M gives you the versatility to build a wide variety of engine combinations.
The Big M is fitted with Billet Steel 4-bolt main caps for ultimate bottom end strength.
FEATURES
• Deck Height: 9.800”
• Bore Size: 4.250” with siamese extra thick cylinder walls to resist cracking and improve ring seal (minimum .300” thick with 4.625” bore).
• Uses +.300” tall lifters.
• Mains: 4 Bolt Steel Billet caps have splayed outer bolts for extra strength.
• True priority main oil system lubricates the main bearings before the lifters. Our stepped main oil gallery (9/16“ to 1/2“ to 7/16“) increases the flow of oil to the crank at high RPM, and our front oil crossover eliminates internal oil leaks around the distributor shaft.
• Lifter valley head stud bosses prevent blown head gaskets.
• Dual oil pan bolt patterns fit standard and notched oil pans.
