I have a rebuilt 390 in my 76 F-150 4x4 and am having problems getting my intake manifold to seal. It has a performer 390 on it and ive had the stupid thing off twice sense I rebuilt the motor and no matter what I do im always getting a leak, is it possible that my manifold is warped or what. I wouldnt mind so much but it causes a low RPM stumble. Ohh and for ne one who thinks bad of a 390 let me tell you im on my third rear driveline and who knows how many U-joints and all I have is a small cam and a 4bbl.

 

Which gaskets are you using. I think you have to use the non permatorques with those. You do with the RPM anyway. Might want to try a set of felpro 1247 gaskets. Do not overtighten these as they will fail.

 

I've had to return two Edelbrock intakes because the bolt holes would not line up. And they were different both times. Place the intake on the engine, use the ditributor to center the manifold. If the bolt holes in the manifold will not line up, you may need to drill them out a little. Remember, if the block was decked, or the heads milled, you might need to mill the intake as well in order for everything to line up.

Reggie

 

 

>I have a rebuilt 390 in my 76 F-150 4x4 and am having
>problems getting my intake manifold to seal. It has a
>performer 390 on it and ive had the stupid thing off twice
>sense I rebuilt the motor and no matter what I do im always
>getting a leak, is it possible that my manifold is warped or
>what. I wouldnt mind so much but it causes a low RPM
>stumble. Ohh and for ne one who thinks bad of a 390 let me
>tell you im on my third rear driveline and who knows how
>many U-joints and all I have is a small cam and a 4bbl.

My Performer 390 leaked. I wound up measuring the length of the bolt hole with a dial caliper and finding bolts and washers that would take up the length without being too long.

The stock intake bolts from a 2V were too long for the Performer.

period.

art k.