I have an 86 f150 with a 302 EFI and 3 spd. OD. It has been leaking oil for quite some time now but i am not sure where it coming from. I have replaced the valve cover gaskets, rear main oil seal, and the front timing cover oil seal. Is it possible for it to be leaking from the intake manifold end seals. Thanks for any help.

 

You Bet! On my '86 EFI 302, the rear gasket on the lower intake had a curve in the gasket material. The problem was the block and intake mating surfaces are straight.
A gasket with a curve in it, and a straight lip on the casting = oil leak.
Reamer

 

Yes, if someone didn't pay attention when they put the intake on, it can leak. IMO Ford used a crappy 4 piece gasket set that seals the intake - lots of possibilities for water and oil leaks. If it's leaking out the back, it's probably the 's' shaped seal on the back edge of the block.

 

I thought that it might be what was leaking because I have antifrezze leaking from about the same area. Oil and antifrezze runs down the right side of the engine and drips on the exhuast pipe crosses over. It burns off and smells really bad through my heater/defroster.

 

That sounds like a head gasket....leaking antifreeze.

 

There are water passages near the end of the intake manifold too. The best tip I ever got was to use the side gaskets, but throw away the end gaskets and use a thick bead of silicone instead.

 

I agree with Dave I have had a few 302's and used the gaskets that came with the set and it seemed to always leak from the back gasket, after replacing my share of them I was told from a Ford GURU throw the end gaskets away and use a thick beed of RTV black, do not use blue,red, nothing but RTV black lay the beed on the block and set the intake down on there, its a one time shot deal, if it moves the slightist little bit, start over. I have had great luck with all the ford motors I've built since then using this method.