What are you willing to change them out to ? and what tire size makes a big difference to final ratio.
If you don't overly care what performance just do a 9:1 cr 600 cfm on a performer intake with say comp xe250h or similar cam decent headers with mild stall and 3.23-3.55 gears and call it a day.
If I was able to get a set of 302 heads, would it be worth my while in getting them and go with 1.88 intake and 1.600 exhaust valve's along with the other modifications you mentioned or just stay with the stock heads
