I just put a 331 in my 65 fastback. The engine runs strong but has an inconsistant idle. I think I've narrowed it down to a vacuum leak where the intake meets the head on the passenger side (I used the old carb cleaner trick). I have an Edelbrock RPM Air gap intake and World product windsor jr heads. I put the front and rear gaskets pieces from the intake gasket set on and now I'm reading that I should not use these front and rear gaskets, instead I should use RTV. Also this is my first ford, I've never used sealer on intake bolts a chevy. Is it neccesary ona ford? Do ya'll (yes I'm from Texas) think that the end gasket pieces are causing the intake not to lay on the head correctly? Please help I don't want to pull this intake if I don't have to. Thanks.

 

Doubt that is the cause of a vac leak,,, but it may be possible....

The big problems with the end gaskets is that they can squeeze out when you torque the manifold.

This is a particular issue when either the heads or block has been milled down.

 

If you sprayed and the idle surged, then you're leaking. Pull the intake off and put it back on, and make sure to detorque and torque the manifold in the correct sequence/steps. And use Ultra Grey RTV for the front and back of the manifold, that stuff is greyt.

 

When I spray the carb cleaner the idledrops, it does not rev up. Is this a leak?

 

if the idles changes, you got a leak.

 

Follow this procedure and you'll have good results with your intake install.

http://www.mustangsteve.com/intake.html

Jeff

 

I think the most important part of that writeup (very good by the way) was the alignment studs. Take an old intake bolt with you to the hardware store, and buy 4of the same size, but at least an inch longer. Then cut off the heads (and slot them for a screwdriver if you want). Now you have a set of alignment studs that will REALLY help with installing your intake, especially if you are still running a cast iron one like me