I am ready to pep up my '78 F100 w/factory rebuilt 302. I also have a '69 351W block in the wings to be rebuilt. I already have a Lunati retro hyd roller kit, cam and Holley 4bbl/600ish in the closet that I bought for the 302.
I was wondering what some good aluminum castings, new/used, that I should look at to do a head swap and leave the factory stroke/pistons on the 302 but also to use later when I get the 351W block ready to drop in. I did not rebuild the 302, but I would bet the owner, who was a mechanic, put the stock type with a valve relief back in it. Not sure how small I should go with the quench size... 58cc-64cc in using the stock type pistons using pump gas.
Everything from the basic Edelbrock Performer to Dart Pro1, to AFR and TFS aluminum heads are healthy upgrades over any of the stock Ford heads, I'd suggest you look for something with 1.90/1.60 valves and 60-62cc chambers which will be small enough to provide decent performance on the 302 but not so small it would make static CR too high on the 351.
I would go smaller on chamber size to maximize the ratio on the 302. You can always choose pistons for the 351 to match the smaller chambers. 58 cc's are the norm for the smaller chambers, choosing from 60-62 isn't going to change that much anyway on a 351, it will though limit your choices in heads, possibly forcing you to skip an otherwise good deal. I bought Canfields when I went shopping ten years ago, was about to buy Brodix then, till the Canfield deal popped up. Never regetted the choice I made.
Been seriously looking at the Trickflow Twisted Wedge 170 today... nice head. Seems also Ford Racing goes a long way by CNCing the intake and exhaust runners for a nice price... 5-angle valve job also.
I wouldn't hesitate to use FRP products... they been in the racing business fer a long time. I would almost bet they design the heads and molds and have them poured at a foundry that does alu OEM blocks/heads... not sure if they actually own a alu foundry or not. We have a alu foundry in our lil town... used to be called Teksid, once a Division of FIAT. They were sold to Nemak... they do alu blocks/heads/intakes for several auto companies.
I put on GT40-X heads on a 5.0L with good results. There were the X & Y version with the X version offering more performance which is what I used. Both were offered in 65 & 58 CC versions. I'm not sure how easy it would be to find a set but these heads bolt right up, use stock valve train parts, etc. Add a set of 1.7 RR with your cam while you're at it.
These heads were cast with a different combustion chamber shape then the iron GT40 heads for more turbulence and better combustion. For use on a truck and a mild cam these heads should work well.