\6 swap question

2 Darts said
According to the Mopar 6 cylinder manual, the only engine affected by the crankshaft flange change was the 170 CID. They say all 198 & 225 used the larger flange.

That is incorrect. the 170 and 225 both had the crankshaft flange/pocket change between 1967 and 1968, same as the small block. The 198 engine was not even in production at tha time, so yes, it only came with the large crank flange/pocket.

The best heavy duty crankshaft (same source) comes from the truck. The forged crank was phased out at the end of the 76 model run. The two cranks are not interchangeable (balance issues). In the stamping on the block look for 225E for a cast crank engine.

This is sort of correct. It was not all truck crankshafts. just the 225-3 truck engine, which had a shot peened crank, according to chrysler, but not many have ever seen one. Also the cast crank has different size main and rod journals, then the forged crank. so it is not just a balance issue.

IMHO, having a cast crank engine may not be such a bad thing. It depends on how the car is to be used and what kind of power do you expect to get from the engine. Though the forged crank is the stronger of the two types, its mass works against it when the engine revs up. The cast crank should rev up quicker than the forged crank, all else being equal.

This is totally correct, if I remember correctly, the first slant door slammer in the 10's had a cast crank.

The Mopar slant six manual has a lot of good stuf in it, but there are also some mistakes.