2001 XJ Thrush Welded " very quite"

[kf_chris]

I don't know about the cam. I'd think that putting one in would help, but it (mine I mean which was chosen for low end tq) was put in when the engine was apart for the stroker build.
I'm sure you can search for which cams are best for the 4.0 here and find a lot of information about the cam swap

 

[old_man]

But will a cam do for performance? Its would be expensive to put one in ?

Other than displacment, a cam is the biggest performance improvement you can do.

 

[tron97]

My magnaflow without a cat, with a 3.5" tip sounds beastly. Has a beautiful idle.
Buddy with a thrush welded sounds like garbage.. like the old saying..
you get what you pay for..