Here are the lengths for early round port version of the Edelbrock RPM heads as delivered by Edelbrock.
I e-mailed Edelbrock tech in 1999 and asked for their specific valve lengths, this was the reply direct from Edelbrock:
87cc version
5.093" intake / 5.110" exhaust
72cc version
5.213" intake / 5.230" exhaust
Keep in mind these are the reported lengths of the valves used by Edelbrock themselves in their assembled cylinder heads, again in 1999.
Some aftermarket valve lengths will vary slightly for the same application.
From this I will presume the springs seats were probably not machined deeper....
"Looks like water is fairly close under the spring seats. Probably wouldn't risk cutting down more than .030" or so for clean-up."
This comment made here on PY just after they were introduced.
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__________________
'70 TA / 505 cid / same engine but revised ( previous best 10.63 at 127.05 )
Old information here:
http://www.hotrod.com/articles/0712p...tiac-trans-am/
Sponsor of the world's fastest Pontiac powered Ford Fairmont (engine)
5.14 at 140 mph (1/8 mile) , true 10.5 tire, stock type suspension
https://www.youtube.com/watch?v=qDoJnIP3HgE
Last edited by Steve C.; 01-02-2022 at 06:05 PM.
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