389 heads on a 455 huh? Don't see that too often. Looks like Jack and Geoff have you on the right track.
Definitely check for spring bind. Should be at least .050 between the coils at full lift.
My suggestion would be to read this page on determining valve train geometry http://www.pontiacstreetperformance....traingeom.html
You will need an adjustable pushrod like this :
http://www.compcams.com/Technical/Cu...g/HTML/293.asp
One more question - Do your 389 heads have the bottleneck rocker studs or the straight ones? The latter type would make things much easier.
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1969 GTO hard top ~ Std bore 400, '70-RA3 block, 670 heads, Bal. & Blue... M22, 12-bolt w/3:55s
Last edited by GRX; 08-02-2006 at 04:50 AM.
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