There is no difference between the V8 and the 4.3 liter 4L60s. The subtle changes in the 700 are similar to the differences between the LS1 in the Camaro and the LS1 in the Corvette. Same thing but little changes add up to big differences in performance. The only 700s that were used behind 2.8 liters had a goofy bellhousing. They won't even bolt up to a Sy or Ty and had a miriad of failure issues and were consequently done away with (era of the 7 vane pumps and no aux valvebody). The only 4l60s that should even be considered for rebuilding are 88 and up models. The case was changed in 87 1/2 model year to accomodate the aux valve body. The 87 and prior valve bodies don't even have provisions for ecm controlled TCC lockup. The 2-4 servos will fit all 700 cases. That is why they sometimes end up in rebuilt units and then end up in someone's SyTy.