302 heads are LA heads that came on a 318 only.
J heads have a 915 casting number.
No. But it may help get to the target goal for power.
Key word - may.
Depends on the plan of attack. Someone could also say it’s half way there. Next is a cam and headers and be done with it.
I try very hard not to settle on things because when you could have and settled, you always say to yourself “I could have had….”