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Part number: 31243354
Product Details
Dart 31243354 Big M Gen VI Full Water Block
Products specifications
Cyl Bore 4.25in
Deck 10.2in
Big M MRK IV Full Water Block

With deck heights of up to 9.800 and 10.200 and bore sizes of up to 4.310, the Big M Full Water Block gives you the versatility to build a wide variety of engine combinations. A true priority main system oils the main bearings before the lifters for added reliability. The Big M Full Water Block is fitted with 4 bolt main caps for bottom end strength.


  • Standard 9.800 and tall 102.00 deck heights available.
  • Standard 4.250 or 4.310 bore sizes.
  • Uses +.300 tall Gen VI style lifters. Modification for MRK IV style available.
  • Scalloped outer water jacket walls improve coolant flow around the cylinder barrels to equalize temperatures.
  • True priority main oiling 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.
  • Oil filter pad is drilled and tapped for an external oil pump.
  • Lifter valley head stud bosses prevent blown head gaskets.
  • Mechanical fuel pump boss, clutch linkage mounts, and side and front motor mounts simplify installation in any chassis.
  • 4 bolt main bearing caps in ductile iron have splayed outer bolts for extra strength.
  • MRK IV blocks use the 2 piece rear seal design, while Gen V and Gen VI blocks use a 1 piece seal and a different timing cover pattern.
  • Standard BBC cam and main bore.
  • Coated cam bearings, freeze plugs and dowel pins are included.
  • Dart blocks are available fully finish prepped.
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