I had a stripped seat bolt on the 79 camaro bucket got, and I used my craftsman set like linked above, pulled it right off.
I bought them to try and a broke tbi bolts on my 88 they weren't small enough to fit.
Now I've got like 5 brok eones in the olds 403 heads sadly several of those broke off flush with the head, I figure no way will an e-z out or whatever you wanna call them extractors would work. I think I'll end up drilling them out and heli-coil or maybe on some the way th eolds head is made you can get a nut on the backside.
sbc stuff aint gonna happen.
I was told wd-40 rust release beats pb blaster and all others, can't confirm.
heat works great if you got an oxy/ace type torch propane will put some heat on it but not get it glowing red like a nice cutting torch.
You can also weld a nut on if you have a welder. That also helps because it will get said stud red hot as well.
I myself plan to try some wd-40 rust release stuff, not the OG wd-40 and also may give those sockets a try never thought of trying them on the heads to be honest.
Also they make a stud extractor, that works off a 1/2 drive ratchet, breaker bar etc. I have one but not mines brok eon the end for some reason.