Heat wrap supposedly holds in so much heat that on mild steel headers they can get so hot they blow a hole in them. Thats what i've always heard anyway.
BTW, I think you will find you still have a ticking from your TFS heads.
We all do.
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1988 Mustang GT
12.34 @ 112.66 on motor
11.34 @ 125.06 on the sauce
1992 BadAzz Wrangler
1993 Explorer
See my car at:
www.mustangworks.com/cgi-bin/moi-display.cgi?179