intake swap Questions

[truck7575]

So is it even a header or just a stock manifold. Do these all crack too like my manifold did?

 

[joe_peters]

So is it even a header or just a stock manifold. Do these all crack too like my manifold did?

All exhaust headers on the XJ 4.0s will end up cracked if you don't take steps to prevent it.

When the engine or transmission mounts get tired/worn, and the unibody flexes, or the engine mount bracket bolts fall out or break, then they crack.

You can make sure and check your mounts frequently--always a good idea--and you can add a flex section to the downpipe to relieve stress on the header.

Flex section sample: http://www.cxracing.com/mm5/merchant.mvc?Screen=PROD&Store_Code=CXR&Product_Code=FLEXPIPE-250x8

Good place to install the flex section is where the downpipe runs parallel to the front axle when going from left to right.

EDIT: So is it even a header or just a stock manifold.

It depends on what your definition of "is" is...

Once upon a time the majority of exhaust manifolds in the U.S. were a cast piece where each cylinder doesn't have it own tube or runner attached to it. Exhaust headers, where each cylinder has its own runner, were a "performance" modification. Along comes emission standards and engineers started looking for ways to regain "performance" lost in efforts to reduce emissions--the production exhaust header is born. Well, that's my story and I'm sticking with it.