ddd777

My car originality had one tailpipe.

The person who had it before me kindly converted it to 2 (with and X) and clumsily plugged up the intake hole (see first attached image).

Is what I am looking for the W/Z manifolds with casting numbers 402294 and 402295, or something else?

Mine clearly has a 4, not a W, and looks different from the ones that Fusick sells.
http://www.fusickautomotiveproducts....number=EM350JR
The left side does not have a Z (see second attached image).

I found a reference that stated that the W/Z: "...design, which features a divider between the center exhaust ports."

Is that what I want, now that it is a dual pipe, or something else?

Can I just swap out the right side and leave the left alone - or should they match with the divider between them?

Before I go posting in "Parts Wanted" I need to figure out what it is that I actually need....

Confused....

11971four4two

The W/Z manifolds will not work on your 350 Olds. I would guess fusick sells the factory style cap to block the crossover on the right side manifold. When I had the exhaust done on my 72 the exhaust shop made me one.

kitfoxdave

What you have is similar to stock configuration... they came from the factory with a plugged crossover port. Thornton makes an exhaust manifold without the crossover for the 350. (350 JR) the exhaust port out the back is a little larger diameter than stock. I swapped mine out and hope to post some pictures this weekend. (they were not on my camera card when I left the house! Wrong card!)

joe_padavano

This comes up frequently. Factory W/Z big block manifolds will NOT fit on a small block. Yes, they will bolt to the heads, but the W/Z manifolds are designed to take advantage of the taller BBO deck height. When you put them on a low-deck SBO, they hit the oil filter and motor mount.

ALL factory dual exhaust SBOs, including W-31s, used the standard SBO exhaust manifolds. There is a cap that goes on the crossover port on the passenger side manifold for dual exhaust use. There are NO factory dual exhaust SBO manifolds except for Toro manifolds, and these have unusual exit port angles due to the need to clear the transaxle.

And since the Thornton manifolds always come up in one of these threads, read these. Just be sure you understand what you're paying dearly for if you decide to go that route.

https://classicoldsmobile.com/forums...manifolds.html

https://classicoldsmobile.com/forums...manifolds.html

https://classicoldsmobile.com/forums...manifolds.html

https://classicoldsmobile.com/forums...manifolds.html

1970supremevert

I found this on e bay 29.00 , not mine..
Hope this helps

Good luck

joe_padavano

Most of the usual repro houses sell them, though for more than the ebay price.

ddd777

thank you very much.
turns out inline tube has them for $26.
helps to know what it is that one is looking for....

ddd777

Not to beat a dead horse, but I figured I would add this info I found at 442.com/oldsfaq/ofexm.htm

and an image from the 1972 assembly manual:

65B01Delta

I have a nice set of 69 350 exhaust manifolds.

kitfoxdave

here is a picture of my rh thornton...
just for your information.

I am not promoting or knocking them. I am refurbishing my car as a nice Cruiser and did not want the hassles of the headers.
(if they were not a hassle there would not be so many posts!)

I doubt if the heat riser shroud would fit over the stiffening ribs on the Thornton. The openings that match up to the exhaust ports on the heads are larger than the head openings. (roughly 1/16 to 1/8 per side of opening)

There is a divider in the middle port. I had a divider welded into the heads when CutlassEFI had the machine work done.

I am not going to the track with this car. Maybe a few sqhels between stoplights...
I hope this was helpful to you.

Dave