I'm looking to get my stock heads ported to accommidate a LT4 Hot cam
with 1.6RR's this would put valve lift at I-0.535 E-0.525 and duration at 0.050 would be I-210 E-228

Can anyone tell me the flow numbers I should be aiming for, and if I can get these numbers out of LT1 heads

 

Correct me if I'm wrong, but wouldn't it be easier to match the cam to the
heads, instead of porting the head to match the cam?

I don't mean that in a rude way, I'm being totally serious.

In any case, you'll want as much flow happening at valve lifts of usable duration.

IE: More head flow at 0.300", 0.400" lift, rather than 0.500", 0.600" with a valve
lift that you specify.

At peak valve lift, the duration is short, therefore you want the head runners
to be modest in volume. I don't see any major porting in your future. Maybe
200 c.c.'s for intake (assuming a 383 turning less than 6K RPM?).