I had a set of '69 #16 d-ports race ported years ago by Jerry Goodale and when tested on my engine builders bench at the time they flowed 291 at .600 lift (28").
Intake valves were 2.125".
Looking back I suspect that number could be a bit generous. A few years ago I sold the heads to Paul Knippen, on his bench they were 278-282 cfm at .600".
(he tested 8 ports)
However different flow benches, and the type of bench, and with different operators you can and do get different numbers. Sometimes all over the map !
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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)
Best time 5.13 at 140 mph (1/8 mile) , true 10.5 tire, stock type suspension
https://www.youtube.com/watch?v=qDoJnIP3HgE
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