Alum. head question.

[GMH454]

If they are from a L-89 they would be perfect for a good street engine.
Check that they have the winters snowflake, and the shape of the exhaust ports, If square they are right, if round, they are second gen, ZL-1 style heads, and benefit from high RPM big cam. Think twice before using them on a street engine.
I changed to them from good street heads, and was disappointed. Lost my bottom end torque.... round 4000 it gets to be fun, and it is a restored drag/street car, so that is okay, its just that the trip to the track will not be a lot of fun.
Good luck.

[Stitch]

Don't you mean the intake ports ?

[TimG]

Intake ports are all square on aluminum heads, exhaust ports differ if I remember correctly.

[Stitch]

No , low and mid perf BB heads had oval intake ports and bigger chambers , all high perf BB heads had rectangle ports and bigger valves . But by fitting the 2.19 and 1.88 valves into oval port heads and a little chamber and port work you'll end up with some low buck stump pullers [img]/ubbthreads/images/graemlins/laugh.gif[/img]

[GMH454]

Stitch, we are talking of GM winters alloy heads here.
They all have the same intakes, it is the exhaust that differs.
There never were any low or mid perform. Alloy heads.
[img]/ubbthreads/images/graemlins/scholar.gif[/img]

[Stitch]

Ooops there I go again leaping before I look and ending up with my foot in my mouth , maybe I should just stick to reading the posts and not replying [img]/ubbthreads/images/graemlins/blush.gif[/img]