ProComp/Speedmaster aluminum heads

Sometimes all they’re here for is to make sure there won’t be any “problems” that could have been easily corrected before they were installed.
And the one set of SM SBM heads I had here fell into that category.
That set got nothing but new valve seals and a couple of springs shimmed up.
The big wide seats aren’t the best for performance, but as long the the runout is decent, it’s not going to cause any problems.
Guide clearance was a tick over .002”.
Again, not fantastic for new aluminum heads with bronze guides, but it won’t cause problems.

Sometimes they're here for a check over as well as some minor(or not so minor) enhancements........ sometimes not.

Ootb assembled head:
Lift———in/ex
.100—- 61/49
.200—-120/97
.300—-176/134
.400—-221/153
.500—-240/164
.600—-250/168
.700—-253/168

With a proper valve job and a basic bowl blend I’d expect to see a gain of somewhere in the 10-15cfm range from about .400 lift on up.