Cracked Exhaust Manifold

lawsoncl

New member
I just picked up a used 4.0 for the 89 MJ for $350. Professionally rebuilt 25k miles ago. Looks like the exhaust header was welded once, and it's cracked pretty good again. Any recommendations on a replacement?

Can I use an exhaust manifold from a newer model? The newer HO ones are under $100, but the older Renix ones are all over $160. I'd almost rather try rewelding it again instead of shelling out that much.

From reading other threads and pictures, it looks like the later exhaust manifolds will bolt up if you use the right gasket, but there is no egr tube and the output points back about 45* angle instead of almost straight down.
 

rysam

New member
Apn? Cheap and easy. I've had one for 4 or 5 years with no problems I didn't create myself. I would highly recommend a flexible piece somewheres in line. I mounted mine rigid and had a hanger fail which eventually cracked the manifold.
 

lawsoncl

New member
APN doesn't seem to make a bolt-in for the 89. I could only find one for the HO engines, which has the output pointing differently and no bungs for the EGR or O2. Thinking I might just get the Dorman as it's a straight bolt on, then have a shop weld in a flex joint after I'm done with the engine swap. Either way I'd prefer to get this done before I drop the engine into the truck.

http://www.amazon.com/gp/product/B000C123A2
 
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