Whats the differance other than the bore between the 383 and the 400?? the stroke is the same and the block is the same as far as I know. technicaly speaking I should be able to do the same things with a 383 as i could with a 400. I think the main journals are diff and the caps but other than that what else?/
The only difference is the bore. anything you can do to a 400 you can do to a 383. You cannot overbore the 383 to the same bore diameter as the 400 though.