If the rear is from a C4 vett---the lower shock mount will not stand the weight of the truck being carried there without some reinforcement---it was designed strickly as a dampner mount. If you do decide to use it , you can reinforce it by makeing an addition that spreads the load to another area, also you need to use small diameter coil overs to clear the half shafts

I may have some drawings if I can find them

If you want dual coilovers I'd suggest going a different route than the vett rear