99 corvette and 02 ss heads
If the 99 are 853's and the 02's are 241's yes there is a slight difference.
02's will flow a little better.
im thinking about getting the 853s ported, i might port them my self, just polish and blend them out. would it be worth doing that or would the 241s still be better?
Porting is an art and doing it wrong will result in unequal cylinders which is not a good thing.
also how much does a port job run?
Usually a stage 1 (stock valves) will be in the $800 range.
But shop around: Nowadays you can get a Stage 1, 243 LS2/LS6 casting for around $ 1K with 918 springs CNC ported. (TSP, PP, Livernois).

