Are you using a Aftermarket T56, LT1 or LS1 Configured T56 ? Aftermarket and LT1 T56 will be the easiest to install, as you can used normal bellhousing and clutch setup.
If using a LS1 T56, The Flywheel, Clutch, Throwout bearing, Input shaft are setup a bit different.
Suggest you reseach if your not sure a this time.
It is possible that your Trans Tunnel may need so adjustments...
71' Chevelle, 99 LS1/Viper T56,Full Hotchkis TVS,Custom Cowl Induction CAI
84' Z-28 350/T5 71' Nova - LS1/4L60E
, Full Hotchkis TVS Suspension
79' G-30 SWB 4X4 Van, 400cid / TH350 NP205
48' Ford F-1 1/2 Ton Truck, Stock 6cyc/3sp