On some mopar applications, I have heard of a restricted cooler for the transmission cause this condition. You can temporarily by-pas it with rubber hose for a test.
It is possible that a wire is being stretched. IF you can rock the eng/trans in the way that it torques in reverse and make it stall, it will help confirm this.
You can try swapping the crankshaft position sensor with the old one if you still have it.
Sunday, December 23rd, 2007 AT 8:37 AM