The best are
aftermarket aluminium ones..... If you are worried about performance and on a budget don't even bother working with stock heads.... get aluminium ones for a thousand bux... way better value. When you consider how much you will spend to drop in stainless vlaxes, better springs.... you can get the FMS turbo swirl heads you can even run simple stock 5.0 bedestal rockers on them.... its like why bother with the iron ones?
That said... the best thing you can is build a 347 that has 9.0 compression with the heads you have and put al ones on later. It doesn't really matter what head you have on a 302... the 347 is going to stomp the piss out of if hands down in the RPM range you operate a
Bronco in... and the torqe won't even be close. A 347 will bark a set of 35s in four wheel, a 302 not so much.
I am guessing these are roller blocks? If you are working on a budget I would run the stock roller cam and headsand rockers on a 347 and then uqgrade to AL heads with 1.7 rockers and stock cam. If you don't have roller blocks... run a roller cam with retrofit lifters.
If you just runs those engines stock... they will be fine too. Or you can build one with the best stock heads you can find, and then build the other a 347, and with the same cam the 347 will make the other
engine seem silly....
That being said you can find a 351W and rebuild that... if it is a non roller 351W, use a roller cam and retrofit lifters and that will be even better because there is no machine charge for that operation and
parts for that will be like 700 bux.
Before I get grilled here I will say to answer the question the best stock heads to run on a 302 are the 289 heads followed by the 70 351W head and 68 302 truck head that all have 58-62 CC chambers. Iron heads seem to run best with the small quench chamber.
The best cheapo 302s I have put together are real riggers that were accomplished with running a ring cutter around the top of the bore, flex honing the block, and re-ring on the cast valley of death pistons from the 70s Ford tortured their 302s with. Then I would put in a comp cams hydraulic stick with about .480 lift. The only machine shop charge I incurred was for re-doing the heads. For hauling and 4x4 work those engines ran really well. I hope this helps.