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Discussion Starter #1
http://photos.yahoo.com/bc/jjacobs22/lst?.dir=/exhaust+manifolds

Ok, that's a 401 those are (loosely) bolted to. A 6500 rpm high compression 401 that ran fenderwell headers last time around. Since this is a buggy project, I'm more concerned with torque now. Think they'll be OK?

Really my main concern is the uneven outlet location. The right side dumps quite a bit further back. Did I get a mismatched set? Ideally that side would be a little further forward so I could push the firewall forward a little more. Also, one side is set up for a flat gasket, the other uses a donut gasket. Same question, is this normal, or a mismatch.

Thanks-
 

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Normal, mine look identical to that.

Edit: Actually lemme take that back... the passenger side is identical to mine but the driver's side is a little different. My driver's side outlet is farther forward. As close as yours is to the rear exhaust port, that's how close mine is to the two in the center. Unfortunately I don' t have a pic of mine to show you, sorry. FWIW the stock manifolds on my 401 are identical to the manifolds that were on my 304.
 

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that set up is perfectly normal from any FSJ made after 1979. the dside manifold is more compact, reputedly to make room for the the front drive shaft. the ones made before 1980 were near mirror images of the pass side manifold. the early ddise manifold is supposed to flow a little better than the later one, and they are directly interchangable. they both drop on to the down pipe in the same spot.

the flast mounting area on the driver side is for the heat valve, which bolts to the manifold and has the donut recess in it. you'll need one for your exhaust.

a stock y-pipe for an FSJ is really compact. it hugs under the tranny and bolts to the side of the transfer case. it gets a little tight were it dips under the pside drive shaft at the t case, tho.
 

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i did something similar to this on my scrambler:
http://www.4x4wire.com/tech/josh4x4/exhaust/

before getting the new exhaust, i was running (temporarily) manifolds with about 2' of pipe on them...basically they were open. just driving it around the yard and on to the trailer (to go to exhaust shop), i was sort of dissappointed with the low RPM torque.

after having the single exhaust installed, it was MUCH better. i have 2.25" tubes off of each manifold going into a single 2.5" tube, thru a catalytic converter (exhaust shop had to put it on) and out the driver-side rear corner. no muffler. it sounds good, and has lots of high rpm power and low rpm torque.

matt
 

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If you interested in headers Thorley makes a good heavy, in-frame set of tri-y's 304-401 CJ's.
 

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Discussion Starter #8
TexasBlakeWFO said:
Looks the same as the one's my buddy has on his AMC 360. I wouldn't run a body lift cause your clutch linkage is gonna rub all over it..... but why would you want one of those anyway. :D
No body lift on a buggy. Isn't a tube chassis more of a unibody anyhow?
 

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nobody20 said:
If you interested in headers Thorley makes a good heavy, in-frame set of tri-y's 304-401 CJ's.
I've got a set on my '79 that I've had for over 10 years - they are built very, very well. I'll be putting them on my 401 when it goes in:)

Brian
 

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those are mismatched. the pass. side is a CJ 304 manifold, the drivers side is a chrysler era 360 manifold.

I'd get another cj manifold. if you take them both off to compare you'll see the 304 style manifolds just look like they flow twice as better.
 

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Discussion Starter #11
Thanks for the input. I think it's time to wander over to 4x4 used parts (.com) and dig through his pile. I'm looking for the best combination of flow and central exit with nearly straight down dump.
 
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