Mopar Performance had offered an intake manifold gasket with two thick (.040-.050) shims to block the heat crossover on small blocks.

I never used this kit due the the shims being so thick. What I do is find a large aerosol can and cut my own shims. The ones I have used where about .011 thick. I have done this MANY times and never had a problem.



1971 Factory Appearing Duster 340 11.000 @ 122 mph