Pontiac greatly over rated their compressions on all their engines. If I were you, if your interested in switching heads, get the 85cc KRE d ports. The compression would be in the upper 8s then, and you could run what ever gas you wanted, with the engine as it is now.
Guys have came on here with tuning issues with aluminum heads and a small cam with not much over 10:1 compression. Aluminum heads wont help much. The guys running 11:1 have the induction, cam, and exhaust to move the highest volumetric efficiencies to higher RPMs, spreading the compression out.
The thicker head gaskets make the quench in a range were it will ping worse even though the compression is dropped. That bad range starts around .060 quench, and continues to around .1 quench. After .1 it seems to get better as it increases. But it is no substitute for a good quench. The .060 gaskets generally put the quench in that troublesome range. If your going to drop the compression with head gaskets you have lower it extra, probably about 9:1.
If you switch cams it changes everything. A cam like an 068 with 16s, would likely run on compatible octane to 72cc aluminum heads and the 066.
Last edited by Jay S; 12-03-2023 at 11:20 AM.
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