Another 87 octane/aluminum heads question

redlined said
There's no quench at all now with the .038" gaskets and open chambers on the 308's. In truth I'm kind of surprised it doesn't rattle since the factory issued PCM's timing curve was programmed with lower compression and EGR in mind.

I'm going to retire in a couple years, throw the thing on a trailer and go wheel the country for a while. It may see altitudes from Death Valley to 13,000+. I was limited on cam specs with the factory TBI, the current stick makes about 20" at idle and seems to cause no issues. With aftermarket TBI, a simple Holley Sniper setup most likely, I won't have that limitation and could bleed some low RPM cylinder pressure with different cam specs.

Another question. The '90 LA is somewhat of a hybrid, using basically the Magnum roller cam setup with the LA rockers. I'd like to keep the LA shaft rockers, I'm wondering about pushrod tunnel clearance issues with Eddy LA style heads and the Magnum style roller cam. Any problems there that a little grinding wouldn't fix?

Ah yes, I was thinking 302's with the quench. I suspect the altitude has a lot to do with your running OK.... the effective DCR is around 7.7 at 2900' elevation. And it sounds like you don't have a lot of timing in.

Going to Death Valley? Then I'd find a way to lower the DCR with the Al heads and keep it in the low 8's max and Al heads. But again, communicate with AJFormS; he has run 87 IIRC on higher DCR's. And IIRC MoparOfficial here races some pretty darned high DCR's on iron heads. So there is a body of experience between those 2 to tap into.