318-3 Closed Chamber Truck Heads
I'm going to tear down the engine during the week, I'll go over/ compare the heads with a fine tooth comb next to the STD 318 heads and make sure there are no other differences (galleries etc). Intake bolt angles work with the performer so that's one problem avoided. If all else matches up I'm going to take a gamble and use them. If I run into problems with it leaking, I'll get the manifold welded and machined down the track.