Pre heat, use nirod and cool very slowly. May or may not crack again, always a crap shot with cast iron manifolds. If it survives a few heat cycles it well be OK.

 

I did just that in my 2004 with the 3.5 and haven’t had a problem since. I had a broken exhaust hanger that caused the manifold to crack, so after replacing the hanger and using the nirod on the manifold my problems have been solved. Great suggestion!

 

Thanks MadCrate .Yea, that's what I'm worried about. It cracking shortly after and having to blow more time and gaskets tearing it out again. I'm also worried that a cheap one won't last past a year. Maybe at this point I'll decide with a coin toss lol.

 

Might be worth perusing salvage yards for a used one ?

 

Salvage yard is your best bet. With the work involved in the R and R of those things, I'd hate to see your welded unit not last very long.

 

I've use JB Weld Extreme Heat with good success on many of my ranch truck's and tractor's manifolds.

 

The cheapo aftermarket cast iron exhaust manifolds are good, I have bought them a couple of times before. The parts house can get them from their warehouse distributor.

 

You can weld it but its time consuming. I started with a carbide bit in an air grinder. Clean the cracks really good and make space to weld. The cracks usually go further than you think so grind until you get good metal. I used the oven to preheat to 500. I then used a map gas torch to heat as I welded. I used cheap flux core unit. After welding I put it back in the oven and slowly lowered the temp. Been holding up pretty good. If you haven't already defiantly get the stud kit either way you go. Good luck!