Thread: aluminum heads / gaskets

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There are some machine shop fellows on this site who disagree with what I'm going to say here, but for most of us fellows working on our motors at home, I recommend buttoning up the motor with all torque specs, then removing the intake to inspect the gaskets between the heads and intake. Without expensive equipment, that's the only way I know of witnessing that the gasket material is depressed and sealing all the way around each and every intake port. If you get an INTERNAL leak there, the motor will be pulling oily vapors into the cylinder every time the leak sees suction from the intake valve. You'll never find it by spraying ether or other materials that are used to find EXTERNAL leaks.

Pat and Jerry and other fellows who have access to high-buck equipment can engineer a motor build without sacrificing another set of intake gaskets, but us poor folks have to use other methods to insure that the motor is sealed up inside and outside.

The other recommendation I'll make is to use a high-rise, dual plane intake such as the Edelbrock Performer RPM or Weiand #8116 or the Holley 300-36. All three of those were patterned off the 1969 Z28 intake that was cast in aluminum by Winters for Chevrolet and will make more power on a street motor from idle to 6500 than any other manifold. Weiand changed the design of their Hi-rise and you can no longer buy the 8116 new, but if you find a used 8116 or Holley 300-36, buy it. I found 3 new 8116's for sale on Amazon a few months ago. I posted the info and they were gone in a day or so. There may be more of them languishing on shelves somewhere as new old stock (NOS). When you find 'em, buy 'em.

Edelbrock 7101 for early heads.
Weiand 8116 for early heads.
Holley 300-36 for early heads.
Edelbrock 7116 for L31 heads.
I would use an air gap intake ONLY if I lived in a hot climate. Cooler climes will like the non-air gap better in my opinion.