as I told... PISTONS is all you need to get the old good numbers from BBs. EVERYBODY will say you diff opinions mostly of them are not on budget just on performance, but PISTONS is the only real difference between a 330 HP from 383 and 260 HP from 400.

THEN you can get some more points extra with some milling, porting and cam... or simply headers and intake, you choose.

I bet you can get same 330-350 HP from a 400 than a 383 with JUST THE PISTONS and the basic resto MP HP camshaft, because IS ALL THAT 383 GOT !.

CRANKSHAFT was different to, because 383 HP were mostly forged and 400 are casted, BUT a casted crank can handle it without problem.

we have a "cheap" solution using KB240 pistons what are same kind of stock pistons ( casted, not forged ) but hypereutic technology/design. I woudl say is the only "cheap" solution for 400s we have out of the shelf

KB can get you some forged pistons too, but a little bit more expensive than the KB240.

Then you have Ross, Diamond what gives you teh option for custom built

But PISTONS and yu are done. I can't think somebody wouldn't be agreed on this, being the DIRECT relation with CR, being THE REST of engine is the same than earliers.

2 advantages of 400 beside a 383... stock manifold is already SPREADBORE design, and more displacement... so who can say you can't get 330-350 HP from a 400 with just that piston change ?

anyway I dunno if a KB240 could give you those 330-350 HP rate, because even they are higher than stock 400s, don't know how much they really are againts 383 ones with OEM/Stock 9.5 CR.

I'm not an expert on this, just being LOGICAL.