Rani, I've always heard that the 383 is better than the 400, However I've never had a 400 to compare. Now.. The hot lick is to use a 440 crank in the 400 and build a nice low block stroker that will fit easier in A bodies, or any body than a 440. A well built stroker can run circles around most 440's as well. I'd like to get my hands on one and build a 470 as a spare.