I posted the following in the 335 forum, I've not gotten any replies there.
Thought I'd run it here. The truck is a 79 F150 4x4 with a 351M and a NP435

I've been chasing a ticking sound in my 351M. I took the truck to a pro mechanic who promptly said exhaust leak. I kinda thought that initially as well but couldn't find an obvious leak. It seemed to be coming from the drivers side, so I've decided to take off the exhaust manifold to see what I can see.

I've successfully gotten the drivers side manifold off without snapping any bolts. It appears that there wasn't an exhaust manifold gasket. It looks like there might be a bit of a carbon trail near #8 exhaust port to bolt ear.

My engine seems dead stock with cat and single exhaust. I've been tempted to remove the air pump and have dual exhaust made, possibly with headers. I'm, worried about clearances with headers as my truck is a 4x4 and has a side fuel tank. My thought at this point is to utilize the stock exhaust manifolds. Sound is more of a criteria to me than HP. I've had a great sounding 302 and have a wonderful sounding 390 with stock exhaust manifolds. I've heard it said that iron manifolds have a more pleaseant sound than headers. If I remember right, I ended up installing the manifolds on my 390 without exhaust manifold gaskets after having a machine shop mill the exhaust manifold mating surface flat. This was nearly 10 years ago so my memory is fuzzy.


What should I do before reinstalling the exhaust manifold?
Have it machined?
Were exhaust manifold gaskets used?
Is there a high flow cat 2in-2out available that would function like an Xpipe?
Anybody used Fenderwell exit headers? Will I have to fuss with brake lines If I get them?
__________________

 

Just an FYI - many engines came without exhaust manifold gaskets from the factory. That's why you didn't find one.

 

FEL-PRO Part # MS90526 {Set}