Factory roller 360 and 308 head questions.

dodge freak said

I have a set but they are the 547 or something like that. They were from MP and have no air hole in the exhaust ports and 2.02 valves.

My heads were 69cc before I had them milled .030. That made them 63cc.

I am with you about the newer rocker arms. I believe the shafts are better for higher rpms. Just get the iron adjustable rocker arms and push rods.

I am very happy my 318 has them.

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The other heads you have may be 576 heads. They are non-emissions, over-the-counter only replacement versions of the 308. They were available from bare 1.88" intake valve castings to ported, milled assemblies from Mopar after the 308's were used up. Aside from the "air hole", I haven't seen any other differences from the 308's.

They make good power with the right combo. Exhaust ports are more efficient than older 340/360 heads. Which heads, between the newer and older shaft-style versions, are better is debatable. My engine builder has run pretty fast in IHRA Stock with 308's and he recently built a very similar engine for me, but using older heads. It will be a while before we have a better idea how each works for our application. But the newer heads should make more torque.

The best thing you can do for small block heads is bowl work and blending in that area.

I'd check with Comp Cams about using OEM lifters. But I would guess that their versions would work better. (Anti pump-up) Springs too.