I have a 69 Cougar, which the valves needed replacement. The heads were replaced on engine, then 2v manifold and carb. were assembled. The car ran fine for a short time, then ran poorly. It was determined that There was a vacuum leak, which caused the engine to run from 1 plane of the manifold, and would not fire on the other plane ,effecting cylinders 2 ,3, 5 & 8. Since the gaskets looked to be ok, it was assumed that the manifold was cracked internally. (no external cracks visible) No surfaces were machined on heads or intake, and looked flat when a straight-edge was placed across them.
I was able to locate a 351W 4V manifold. When assembling to engine, it matched, and fit, but the 4V manifold used 12 bolts, where the 2V used 16! Now, I still have a massive vacuum leak at edges where intake , gaskets and heads meet. (bolts were all tightened to spec @ 23 ' #s) Any ideas? And why would a 2V manifold use less bolts than a 4V? You would think it might be the other way around! Thanx for any help. DOK
I was able to locate a 351W 4V manifold. When assembling to engine, it matched, and fit, but the 4V manifold used 12 bolts, where the 2V used 16! Now, I still have a massive vacuum leak at edges where intake , gaskets and heads meet. (bolts were all tightened to spec @ 23 ' #s) Any ideas? And why would a 2V manifold use less bolts than a 4V? You would think it might be the other way around! Thanx for any help. DOK