Quote:
Originally Posted by OldSoul_YoungBlood
So what would be the consensus on a head swap...
The #11's original to the engine are listed at 8.8cr but have pressed studs and do not have the most outboard exhaust manifold bolt holes.
The #47's I have from the 69' are listed as 8.6 c.r. but have threaded rocker studs and outboard exhaust manifold holes, also noticed single wound springs without a damper and shims perhaps matching Erson componentry from a cam kit? (not saying they don't need to be torn down but they get me closer to the goal post on potential machining costs...)
Is that .2 listed CR on the specs between them even a concern, seems that there's a lot of variance in real world cc vs what's "in print" for Pontiac head specs.
will at least cc the #47 heads since they are on a shelf anyway but i don't really want to pull the #11's in the middle of cruising season just to get a definitive answer.
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Just FYI if you read through archived 350 threads, the #11 heads are reported to be 88-92 cc. Despite the claimed 8.8:1, the truth is probably closer to 8.0:1. The 47s may not be much different - others might know.