351W intake interchangeability through the years?

[Ken Blythen]

The 2-barrel intake on my 351W has some corrosion pitting around the water ports & possibly a crack; it has a casting # D9DE-9425-CB.

I have access to an earlier intake with the casting # C90E-9425-F (apparently a cast iron Mustang/Mercury Cougar intake).

Can anyone tell me if these two intakes will swap satisfactorily? I'm not worried about the early intake being non-EGR.

On RockAuto, the gaskets listed for '69 & '79 have different part numbers.

Thanks

[Ken Blythen]

Just discovered (thanks to Conanski) that the '69-'74 heads & intakes have different bolthole patterns around the cooling ports.

[Gary Lewis]

Just discovered (thanks to Conanski) that the '69-'74 heads & intakes have different bolthole patterns around the cooling ports.

That would answer the question. Glad you found that.

[85lebaront2]

That would answer the question. Glad you found that.

From what I remember from the original Muscle Parts catalog, the later intake would work on the early heads (improved head for 289/302 was to use the 351 head as this was a 1969 catalog) difference was 4 more manifold bolts on the 69-74 heads, anything that covered those would work, but using an early manifold with bolt holes there would result in a massive water leak.

A thought, if everything except the extra holes fits, tap and plug the holes.

[PetesPonies]

From what I remember from the original Muscle Parts catalog, the later intake would work on the early heads (improved head for 289/302 was to use the 351 head as this was a 1969 catalog) difference was 4 more manifold bolts on the 69-74 heads, anything that covered those would work, but using an early manifold with bolt holes there would result in a massive water leak.

A thought, if everything except the extra holes fits, tap and plug the holes.

THere were extra holes added...BUT all will still fit. Now you're in my wheel house :)

[Ken Blythen]

THere were extra holes added...BUT all will still fit. Now you're in my wheel house :)

Thanks for the replies.

If I did adapt this early manifold to fit, are there any downsides (other than weight).......like flow, height, etc?

[Gary Lewis]

Thanks for the replies.

If I did adapt this early manifold to fit, are there any downsides (other than weight).......like flow, height, etc?

I wish I knew. But it is pre-EGR I assume. Is that an issue for you?

[Ken Blythen]

I wish I knew. But it is pre-EGR I assume. Is that an issue for you?

No, we have no emissions testing; I've already removed the EGR. The early intake would be slightly tidier, not having the EGR ports & a block off plate.

[Ken Blythen]

No, we have no emissions testing; I've already removed the EGR. The early intake would be slightly tidier, not having the EGR ports & a block off plate.

Ex-Mustang cast iron intake installed! (It's a heavy sucker)

I drilled, tapped & plugged the extra four bolt holes as per Bill's suggestion, & it fitted perfectly using gaskets for the later heads. This will be the end of the aluminium intake's corrosion/seeping problem.

Thanks for the help!

[PetesPonies]

Ex-Mustang cast iron intake installed! (It's a heavy sucker)

I drilled, tapped & plugged the extra four bolt holes as per Bill's suggestion, & it fitted perfectly using gaskets for the later heads. This will be the end of the aluminium intake's corrosion/seeping problem.

Thanks for the help!

When installing an intake manifold, aluminum or cast iron . . . . always wipe both surfaces and both sides of the gasket with RTV at the water ports. I used the word "wipe" because you don'r want a lot, but you want enough to make a seal. You must break the surface tension of the cleaned manifold and gasket. You put on RTV and move it around until you see that it is attaching to the surface. Then you must assemble quickly. This is easier seen that explained, but I never have leakage problems do it this way.