400 stroker or 440

I'd use what you have. Less machine work= less cost. The 440 already has a 3.75 stroke and if you already have one you don't have to bother locating a 400 block. I have three 440s in my garage now so thats what I use. Spend your money on some decent heads like INDY EZs or maybe the new Edelbrock RPM Extreme. The Stealth heads from 440 Sorce are imported (probly Chinese) and the regular RPM heads are not much different than factory iron heads.