I am trying to find out if i can use some exhaust manifolds ive found through facebook marketplace. Ive been told to use w/z manifolds to make it fit.

Most that i see have r separate ports per manifold, yet the ones ive found (x/y manifolds from a '68 442) only have 3 ports, the middle 2 ports having no wall between them, merging into a single double sized port.

The engine it is going onto is a '73 455 out of a delta 88.

Are there any issues mounting these, do i just need the proper gaskets to match the 3 port design?

 

There were no gaskets from the factory.
389269 X is a 1965-68 A-body LH big block manifold.
398706 Y is 1968 only A-body RH big block. It is equivalent to the 389268 W RH manifold used 1965-67, but this one has the ribs for the hot air stove first used in the 1968 model year.

This will work, but given a choice, the 1969-74 manifolds with the internally divided runners will flow a little better.
402295 W is 69-72 A-body LH
402294 Z is 69-74 A-body RH
412287 X is 73-74 A-body LH and is equivalent to 402295. Do not confuse this with 389269 X or 406301 X, which are not the same. This is why I prefer to use the casting numbers, not the letter.

 

Hello Joe (or anyone else). Hate to tag onto this old thread, but I've got a question related to the OP's manifold.

I've got a 73 455 and I have a need for a L manifold similar in design to the OP's R (389268 W RH)...where the outlet sweeps back instead of down. Can you recommend one?
thanks for any assistance,
~martin