AFR 227's on stock short block?
 

I've got a set of Comp ported AFR 227's assembled with an LT4 intake and Vortec YS Trim supercharger. I picked them up to replace my stock ported LT1 heads on my old high dollar 383 LT1 build I had in my 95 Camaro, but never got around to using them. I sold the Camaro with the stroker motor but still have the stuff. The Supercharger was for a C4 Vette to begin with, and I happen to have a 93 6 speed C4. So I was thinking about some Impala head gaskets, a custom cam, and run the vette on motor for a while before I start dealing with the headaches associated with making a blower car reliable and tunable.

Question is, I'm pretty sure these heads are going to be way too big for the stock short block, but it wouldn't cost me crap..What kind of gains should I expect with a decent lift cam, new lifters, AFR heads and LT4 intake with full bolt on's? Think it will make 400 wheel or are these heads way to big for the stock bottom end without Forced induction?

Ive got a big ass nitrous system sitting in the garage going to shit too..Ive sprayed anywhere from a 150 to a 300 shot on my LT1 cars in the past with never an issue, so Ill probably throw some bottle on it at some point when I find a decent Digital 6 used...lol

I think it will make decent peak power, but your power band will be extremely small and require very steep gears. Likely it will want more rpm than you want to spin a stock short block. It will also drop your compression below 10:1 regardless of head gasket thickness which won't help.

Put in an RV-like cam and it may be bearable. As said, gears as well especially on a manual car.

unless you run a lot of cam and compression, you will have no bottom end, a LOT of gear may help some but don't expect big gains, a guy that worked at a muffler shop installed 2 inch headers (He made) on an LT1 motor he had in a truck, before it would smoke the tires, after, it was a turd off the line.