[Brock1030]

Have been on the lookout for a set of exhaust manifolds for a 1979 W72 400 engine, part numbers: 10002755 (Left) and 495986 (Right). Have tried Frank’s Pontiac Parts and have been watching EBay, with none showing up thus far. Any one know of either or both of these manifolds available for sale?

Thanks so much!

Brock 1030

[Poncho Dave]

I have manifolds off 77 & 78 w72’s. Never seen those numbers. Mine are 499624 LH, 496002 RH

[Brock1030]

Thanks for your reply. The numbers I listed are from John Witzke's article on these cars, citing that the 1979 cars with the W72 400 had these part numbers. Not sure of the differences in the part numbers you cited on your cars and these manifolds.

[starlightblack]

In B.C. Canada , but should be correct by the numbers.

https://www.kijiji.ca/v-auto-body-pa...rts/1589956555


I have seen a few different W72 numbers on those manifolds including these in this kijiji ad...10002754 and 10002755 are considered correct as are 499, 496 and 495 starting numbers...

[Brock1030]

Originally Posted by starlightblack

In B.C. Canada , but should be correct by the numbers.

https://www.kijiji.ca/v-auto-body-pa...rts/1589956555


I have seen a few different W72 numbers on those manifolds including these in this kijiji ad...10002754 and 10002755 are considered correct as are 499, 496 and 495 starting numbers...

Thanks for the reply, Starlightblack.

Any insights on the differences of these W72 manifolds and others for the other 400’s - higher flow? Other?

Have also noticed an alphabetical letter in the casting following the part number. The manifold you forwarded from the ad has the letter “G” after the part number and appears cast in ‘77. The manifold on the right side of my car is a 496002 and after this part number, it has an “H” in the casting. This one was cast in June ‘78 - which would be right for a ‘79 year car. Wonder though what these letters - “G” or “H” - correspond to? A model year? Other?

[burd]

This is all off a YU 400, I’d like to see the ports in the W72 PCs.

[Brock1030]

Originally Posted by burd

This is all off a YU 400, I’d like to see the ports in the W72 PCs.

Excellent, Burd! This will make for a good clarifying reference point, as one would think with the higher “performance” W72 (with late 70’s GM products, term used reservedly) there would be greater flow volume.

As both the current manifolds - L and R - have issues, lining up correct replacements for the winter project to pull the power plant, freshen and detail, plus add the rebuilt UH code 4-speed, as this is one of the 1100 SE Y84 W72 WS6 4-speed cars. Current pic, added for reference.

[burd]

All that is off my 78 400, I put HO’s on, EFE, heat shield, cat bracket, any other pics you’d like Leme know.

[burd]

Here’s the side with the #’s, they are diff.

[Mpc]

I have a set of 10002754H manifolds off of 1977 TA. From what I have read these are In the middle of performance band. Other words not low performance or at the top of High performance! Am I correct? I was thinking about replacing with headers but I think I will just keep stock manifolds on especially if I'm just going to gain 10 HP.I have the 400 motor.

[78w72]

W72 manifolds are different than non w72? part #s may be different but is there really a difference in flow #s or casting design?

[thepontiacman]

Is this what you need?
F217/F107

Sent from my Moto Z3 Play using Tapatalk
These have H7 dates

[Mpc]

No thanks. I have the manifolds on my 77 TA. I am going to keep them. I was going to replace with Ram air manifolds but can’t get them till January or after. So I will just keep stock manifolds. Thanks anyway! Mike