400 big block

Like MoPer said.
The 400 with it's stock short throw crank can be real good at the street or strip. You have to treat it like a small block. The short stroke crank @ 3.38 will rev real fast and high. They are cast in the 400's so a fordged 383 part would be better for hi horse applications.

Theres nothing wrong with staying @ 400 cubes plus any overbore. KB makes a piston(s) for the 400 with the stock stroke. They cost more than other pistons because of low demand. But in the overall picture, it keeps costs down. No extra crank to purchase like in a stroker if you stay with the cast crank which will hold some good power.
Or extra money for mallory metal in balanceing the assembly, which should be balanced with new pistons overbored or not.

The 383 back in the day was a street terror and the 400 with it's 17 cube advantage will perform just like the 383 did back in the day.

MoPar Muscle mag did a 400 build up with some basic part. Dual plane, 750 Holley, headers and a cam (Smallish) into a rebuilt short block to come up with 400 HP.