Hello BMFH,
I'm ex military, went in country 45 years ago. Rode on PBR's. Didn't stay as long as you did. I saw you retired from wrenching H-53 helicopters in 'Nam, Laos, etc. Glad ya made it, thanks for your service. I picked up on your handle B.M.F.H. it made me laugh. Reminded me of B.B.M.F.I.C.
Back to Pontiacs... A lot of guys here do run roller camshafts in their Ponchos. They have their reasons, I'm sure you do too. I feel foolish telling a guy like you that he might want to reconsider compression ratio a little bit. 11.5:1 is a bit stout for an iron head street engine unless you have deep pockets for racing gas all the time. Those 670 heads will be a tight squeeze on a 455 engine. They're just 72 cc heads. You need some big time octane if you are gonna run them. I think a bigger volume head is the right way for you to go. A set of aluminum Edelbrock R/A IV round port heads would be a better choice for you @ 87 cc chamber volume than the 72CC 670 heads. Your end C.R would still be at about 9.9:1. That's not a problem with aluminum heads though. Quicker heat dispersment and if you run a cam with a little longer duration, that will make it even better.
A roller cam will get you away from having to add additive to the oil for lobe protection and there's no break in. There is a higher cost that goes with them. No matter what cam you decide upon, that high compression number you stated earlier needs to be considered.
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