we have now had a 3.90 diff installed into a srt6 and we just past 200 miles on it with no problem. wow is first gear fast(i mean like you are in first gear for less than two seconds and this is at wide open throttle,.. at the end of a couple city blocks, ,you have gone through all 5 gears and you find yourself doing almost 90 mph ,, still testing and within the next 3 weeks we are installing a 3.90 into another srt6
here is what we had to do to make it fit.
1 remove the rear cover from the 3.90
2 install crossfire rear diff cover on to 3.90 diff
3 car 1, we used the rear half of a limited drive shaft ( the yoke is same as limited)
4 swap the diff just as you would on any crossfire as we have done before (no other mods to the diff.)
5 swap the TCU with one of our special set up TCU.
cost to do this yourself. TCU $600. ,, 3.90 diff $950. to $1500. ,, hardware $100. Yoke $300. or use rear driveshaft from limited ( we got no vibration using 1/2 of the limited drive shaft.
we hope to have it on the drag strip soon. and let u know what a stock srt6 with a 3.90 rear will do.
more info email me amx1397@gmail.com