I have a new, 3,000 mile 2004 Trailblazer 4 wheel drive with 4.2 6cyl w/4L60E.
I also have a 1998 Z28 49,000 w/4L60E, tired, w/ 100's of 1/4 mile passes, still shifts/runs fine, 12.89@108mph last week.

Can I swap the 4L60Es ??
Is the 2004 4.2 6cyl 4L60E as strong/stronger/better than the 1998 Z28 4L60E ??
Will I just have to swap bellhousing/tailshaft/??
Or are the cases just totally different & not doable??

My thinking is that the tired 98 4L60E would last a lot longer behind the Trailblazer.

Hmm, I just found out that the Trailblazer TC will work in the 1998 , at 2,200-2,400 stall, so the input shafts are the same too..

Thanks,
Dave

 

if the harnesses and input shafts matched, it still would not be designed with as strong of internal components. If it works it won't last long at all in the 98

 

what are the differences in hard parts?

 

None, the trailBlazer should have five pinion planetaries, and it will have a short 4x4 tailshaft.
So I don't see the point of tearing both transmissions down to the tailshaft.
You might as well just tear one down and rebuild it.