It should work. I am running the cat back dual system from a LT1 on my 91.
Did it bolt up to the existing 91-93 Exhaust Manifolds or did you have to change the Manifolds too?
1993 Caprice LTZ / LS:
51,000 miles, L05, 3:08 Posi, Harris Prom, Lowering Springs, Bilsteins,
96 Steering Wheel, 9C1 Hoses, Dual Snorkel Intake,
SS Rear Disks, J55 Fronts, High Flow Cats, Dual Exhuast, Fleetwood Horns and Center Console, Roadmaster Rear Door Lights, LED Interior 1992 Caprice Wagon: Black Sapphire/Silver, L05, Tow Pack, 3:23 Posi, 9C1 Cluster, 96 Steering Wheel, Fleetwood Horns, LED Interior 1996 9C1 - Former Whelen Trade Show Car - SOLD 1994 SS - SOLD 1991 9C1 - SOLD