your best bet is put the cab on along with the inner fenders and radiator support and try it.
What he said.
Unless you bought a crossmember kit to put the 'vette suspension in place I doubt you'll find anyone with exact answers that you can rely on. If you bought a suspension kit I'd ask the supplier if they can provide what you need.
If the LT1/4L60e came out of a Corvette be aware that the packages is a little wide and the transmission mounting is different than most.
What Corvette rear stuff did you use? I'm wondering if you will be running a torque bar like is found under a C4 Corvette. I'm guessing C4 because this collection of pieces could have come from one.
