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who knows their 80s-90s Chevy factory exhaust manifolds?

Discussion in 'The Hokey Ass Message Board' started by rustynewyorker, Dec 17, 2011.

  1. I'm trying to find out if the manifolds used on V8 like 85-92 Camaro and Firebird are both the same as used on some like 1983-1986 Chevy pickups. Rock Auto shows me the right side interchanges between the two, but there's no listing for the left for the truck. The only difference I can see is the TPI Camaro has a port for an O2 sensor, the pickup wouldn't have. This type of manifold comes up from the exhaust ports, the right dumps at the rear, the left between the middle and rear ports. It's possible they're the same thing except for the O2 port, so one has a different part number or casting number, and that's why I'm not seeing them as interchanging. The key is if the outlet is in the same position and location.

    Right now it's looking like I may have to hit the junkyards and hope I find examples of both cars in one place - but the odds are against that, not a lot of those F-bodys in the yards here.


    I need to know because I may have to go hunting for a set for my '50 Fleetline. I'm finding that with the '89 Suburban manifolds from the motor I have half installed in it, which drop down from the ports and dump more or less the same as the Camaro type, if I raise the rear of the trans so the manifold clears the pitman arm on the stock steering, then the trans is touching the trans tunnel. If I lower it 1/2" or so so there's at least some clearance at the tunnel, then the manifold is sitting on the pitman arm.

    A set that comes up will solve the clearance problem - if it's a set I can buy a prefab Y-pipe to do my own exhaust with, then I'm in good shape. There is one for the Camaro but it twists and turns and I don't think will work; the one for the pickups is simple and looks like it will work great. Mechanically I want this thing to be as close to the Suburban I took apart as possible, just to save any hassles driving the car and finding parts. It's either this, or try and see if a reverse Astro steering box will give me more clearance, or put a Jag front end on it, but the simpler it is to fix this, the sooner I can drive the car.
     
  2. lowmaster
    Joined: Oct 26, 2003
    Posts: 347

    lowmaster
    Member

    I have put small blocks in stock suspenions on these cars before. I use the chassis eng motor mount kit, trim the upright braces on the firewall, remove the frame mount just under firewall on drivers side and use 79 chevy truck manifolds. These manifolds have and indention that clears the pitman arm nut perfectly. If your pass clears this manifold will match pretty good.
     

    Attached Files:

  3. That's just about exactly what I have on there now, and isn't working. Should work, but maybe because I have a 700R4 in there the bellhousing portion of the trans case is deeper enough to cause the interference.
     
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  5. Here is 92 Camaro 305 TBI Manifolds. The bolt holes are lined up

    On bottom in the 73-80 GM pickup style.

    From my memory,
    GM truck manifolds, 81?-86 Carb manifold are similar to the camaro ones. 86 TBI and 87 are similar to the older style.

    [​IMG]



    [​IMG]
     
  6. squirrel
    Joined: Sep 23, 2004
    Posts: 43,177

    squirrel
    Member

  7. RopeSeals???
    Joined: Jul 2, 2007
    Posts: 444

    RopeSeals???
    Member

    How about the Mid 80's C20 tube header?
    [​IMG]
     
  8. squirrel
    Joined: Sep 23, 2004
    Posts: 43,177

    squirrel
    Member

    55-56 manifolds work, don't they? :)
     
  9. So far the one I can't find a picture of is the truck one that's similar to that Camaro one. That one will get me off the pitman arm for sure, but I didn't realize the bottom of it is angled out - that may put me into the frame, I'd have to go measure again (would be good to know how wide it is). But someone has used those in a 49-52, I saw a photo at Chevytalk.org.

    The goal here basically is if the Camaro one and the similar pickup one are actually the same dimensions, I can use the pipe made for the pickup, on the Camaro manifolds, and wrap it all up nicely.

    I had a couple of suggestions to use the LT1 manifold, and that would probably work, but it would require a custom exhaust - in 1994 GM cars and trucks rated under about 4 tons, all go to a deal where the converter and downpipe is one piece. The Caprice and clones actually have two cats and if they're a single exhaust join together behind them.

    Which, a custom exhaust is not the end of the world, but if I do that I may as well use a manifold with a spot for the O2 sensor. I'd just copy the setup that a guy had on one of my Suburbans, he cut the stock Y off where it aimed backwards and ran straight pipes off there.


    I can't remember if 55-57 manifolds exit to the rear on the left; rams horn won't work on the left side; either way the problem there is even if I do find a set they're going to be in rough shape. And it brings us back to a custom exhaust.


    I have to redo a lot of the floors in this, if I had to I could raise that part of the trans tunnel, too. As it stands the motor's not quite level front to back. But I'm not sure I can get enough of a gap to be comfortable that as the mounts age they won't eventually allow enough motion to cause the manifold to hit that arm anyways.
     
  10. Well, I came up with what looks like a solution. A set used on mid-80s Caprice, and looks like also Monte Carlo/Malibu and clones, will do the job. Looks like the Camaro set, but doesn't bow out like they appear to in the picture.

    These manifolds may be all more or less the same, but the set I just looked at in a Caprice aims straight down. The Y-pipe for these cars probably will not clear '50 Chevy steering because for some reason the left side curves forward around the deep part of the oil pan, but hopefully I can compare a pickup set and see if the outlets are the same and try that pipe out.
     
  11. BBYBMR
    Joined: Apr 27, 2007
    Posts: 613

    BBYBMR
    Member

    I purchased a set (Sanderson) from CE that are made for this swap using the stock steering. Haven't installed the engine yet, so can't comment on fit, but......just sayin'.
     
  12. squirrel
    Joined: Sep 23, 2004
    Posts: 43,177

    squirrel
    Member

  13. BBYBMR
    Joined: Apr 27, 2007
    Posts: 613

    BBYBMR
    Member

    That's the ones!
     
  14. Ravenwood
    Joined: Feb 26, 2009
    Posts: 237

    Ravenwood
    Member
    from Texas

    who knows their 80s-90s Chevy factory exhaust manifolds?

    Well, sure, I have a nodding acquaintance with them. But it's not like we exchange Christmas card or anything.
     

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