Anybody ever used or heard anything about pioneer? I got a set of heads (vortecs) at the machine shop now and he said he was going to drill and tap the roller holes and put screw in studs and shave down the guides and put guide plates also. But I was going to use ARP rocker studs but he said he has pioneers in stock and im not running to big of a cam. Its a ***** thumper cam .509/ 522 lift with 1.5. But I plan on runner 1.6

 

Those are "repair" studs; basically stock-replacement, except threaded, to overcome a pulled stud problem.

Not sure they support guide plates; all the ones I've ever used looked like the ones they use in the exh man to bolt the Y-pipe to. No hex, just an unthreaded section. But they may make some that are different from those, I've never seen any but I don't know for sure.

 

Pioneer is OEM replacement parts, not performance parts. For the rocker studs, they'll probably do just fine providing they're going to be long enough.