I had an I6 with the 7.5" 2.80 rear. At 60 mph it sounded like it was going to explode!
I am dropping a 289 in it currently along with an 8" 3.55 rear. A LOT more work than I anticipated swapping a V8 into the I6 body!
Oh, almost forgot, I junked the three speed transmission and I am dropping a T5 in it from a 94 Cobra. I had to replace the input shaft and bearing housing in order to use the 93 5.0 bell housing so I didnt have to use the adapter plate.