Stock truck pump fits. Just have to run F body block mounts instead of the SBC frame mounts with adapter plates.
Just can't put the fuel lines through the frame in that spot and might need to get some truck AC hoses and have a local shop crimp on some R12 style fittings you can buy off 4seasons ac parts. Rock auto and summit stock almost all their parts.
Working on the swap right now. Have most of it done. Ended up with a bracket (can get the company if needed, using truck accessories) to move the AC up from the bottom. Used an R4 compressor from an 89 Blazer, 82-92 Camaro AC hard lines & condenser. 85SS stock heater box, evap, drier etc. All the Camaro stuff connects with just a little bending.
Had to go high with my AC because of the flipped exhaust manifolds for the turbo.