This forum has been very helpful in solving problems with my newly aquired 1987 f250 hopefully someone out there wil have an answer. I have installed an edelbrock 1406 onto my stock intake manifold, oh yeah 460. I'm pretty sure I have a vacuum leak somewhere around carb and thats why I can't tune engine appropriately. I've thought about purchasing the adapter plate from edelbrock however there is a small area on manifold that is only covered by the EGR plate that was stock on the truck. Without removing this plate I can't install the edelbrock plate and without putting on edelbrock adapter I probably won't get the performance I need. Anyone know what I'm talking about and maybe any fixes. Thanks

 

Yeah I know exactly what your talking about I had the same problem. However you should be able to get a good seal if you keep and seal real well the EGR plate, that's what I did. Personally I cut off the EGR portion and filled it with JB weld, I was in a hurry.

You don't need the Edelbrock adapter if you keep the EGR adapter, and it won't allow you to eleminate the EGR plate, you gotta keep it. Make sure you have the correct and good gasket/seal for the EGR plate to manifold. And any good square bore gasket should do a good job sealing the carb to the EGR plate.

Do what you have to do to get that EGR adaptor to seal, remove or replace the EGR and make sure it's good and flat, the seal around the EGR passages is sketchy.

 

opossum, thanks for the information i figured someone out there would know what I was getting at. At least I won't waste my money on an adapter plate. I know that thing is leaking though. I'm thinking of buying a new manifold possibly an edelbrock an suggestions on which one. Thanks

 

Do you know how to use propane to find the leak? Adjust the carb too lean then take a little propane burner, turn it on low without lighting and if you can add a small hose. Then put it down where you think the leak is, the motor will speed up/run better when it sucks in the propane through the vacuum leak.

And yes I know what manifold I would use/recomend, the dual plane air gap #7566

 

Thanks for the input, you think maybe choke cleaner would do same thing or because propane sinks that would work better or be more accurate. sandkwagers

 

Cleaners aren't really the right kind of flamable, engines really love propane.

 

Good to know if I have any more questions I'll post Thanks again. I'll get back with you if I figure it out or not.