Could some one decode these exhaust manifolds for me?
Numbers are 3959562 and 3959041.
Also if anyone knows what numbers are correct for a 1972 Z28?
Thanks in advance.

Those are ' 71-74 RH manifolds, and ' 72-74 LH ones, and would be correct for a ' 72 Z. They could have AIR tubes, or they might not. I have a # 041 manifold without AIR, and it states that all came with the drilled and tapped bosses!? The actual # is 3989041 though, they are hard to rerad.

[This message has been edited by Doug G (edited 04-23-2000).]

Actually yes and no. The correct drivers side manifold is the 3959041 as you stated. The Z28's never came with the 3959562 manifold, the correct passenger manifold is the 3986330. The 330 manifold was used on (reported) some of the last 70 Z28's made. They were used on all LT1 engines and L82's through the 1971 to 1974 production years. So if you are going by Alan Colvins book congradualtions, you just found a mistake.

Take a good look at the 041 manifold. You will see it has the holes and frame rails for the pins for the heat sheilds that go to a Stove Pipe type heating system. The Z28's Air Cleaner (both Dual Snorkel and Open Element) did not have provisions for the Stove Pipe so they had a Heat Riser at the back of the 330 Manifold. So that is why the 330 manifold was used because it did not have provisions for mounting stove pipes or heat shields.

Both manifolds the 041 and 330 were both available in the AIR Tube version or non AIR Tube version.

Bob R

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1973 Z28 Original Owner
Fully Restored
Member of the Old Farts Club
http://www.geocities.com/bobr73z28
#'s match