What do you think?

The HP 383s made about 335 IIRC, with a "advertised" 10.5 to one compression, you probally have more actuall compression, that .528 is a good grind, my opinion is that it probally could get close to your numbers, but a cheapy set of headers and I would say for sure. I don't think the porting would be as critical on a 383 as it might would be on a 440, given the same head... just turn a few more rpms.....