Intake Gasket Restrictors

[Bruce Peterson]

I am replacing a leaky intake manifold gasket on my '86 Coupe and am hoping someone can clear up the controversy over which gaskets to use. I have cast iron heads.

Manuals talk about and show pictures of coolant restrictors in the gasket. Everyone agrees those restrictors should go to the rear of the engine, but no one agrees on whether I need them at all-------with Cast Iron Heads.

Can't get the gaskets from GM any more. Aftermarket brands are no help either, as some brands come with restrictors for that engine----and some don't.

To ensure I use the correct part, can someone tell me for sure if I should have coolant restrictors with cast iron heads.

[Joe L.]

Re: Intake Gasket Restrictors

Bruce------

This is a tough question but it intrigues me. For some reason or another 1986 Corvettes with cast iron cylinder heads used an intake gasket set that was unique to that application. The cylinder heads were NOT unique as they were the same as used for 1984-85 Corvette applications. The intake manifold was unique to 1986 but it was the same for all 1986 Corvette applications whether they had cast iron or aluminum cylinder heads. I suspect, but certainly don't know, that the gasket set somehow "adapted" the cast iron cylinder heads to the configuration of the 1986-only intake manifold which may have been primarily designed around the aluminum heads.

I'm doing some further research on this subject and I should know more by early next week. I don't know if that will help you if you're trying to get this job done quickly, but, at least, I'll have some more information by then for yourself or anyone else that's interested.

[Bruce Peterson]

Re: Intake Gasket Restrictors

Thanks Joe, I appreciate your response. You are the first one to offer a plausible explanation on why there is so much confusion on this. I'm poised to buy FelPro gaskets which have a part number unique to my car and config. (Those gaskets do have the restrictors) But will wait 'til I hear bk from you, as its going to be too cold in Minneapolis to do anything in the garage anyway.