Difference between 4 & 6 cylinder frames?

TJ's-TJ

TJ Enthusiast
Joined
Mar 28, 2018
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MA, USA
Looking at a 99 4.0L Jeep that needs a replacement frame. Have found a really nice 2002 frame local, but it is a 4 cylinder. Anyone know the differences?
 
The only difference is the location of the motor mounts which can be moved but require welding. 2003 and newer also have a different mounting bolt layout for the steering box.
 
Quoted from @mrblaine:

As for fitment, all 97-02 frames are interchangeable with regard to keeping same motor to same motor. The 4 and 6 cylinder frames are compatible with the exception of the frame motor mounts which can be carefully cut loose and moved from frame to frame.

With your 98, if you don't get another 98 frame, you will have to replace the snubbers under the corners of the grill with snubbers from any other year. The 98 has a small U shaped platform that requires a shorter snubber than the full length versions used on all other years.

I would keep looking for another frame in some condition that doesn't need repair. Bear in mind that if the frame is that bad, you'll wind up wanting to fix a whole bunch of other rusty crap once you get into the swap.

So yes, that 2002 frame will work, but being as though it's from a 4 cylinder, you'll have to cut and re-weld the motor mounts on the frame.