electronically controlled variable displacement

[grumpy old man]

I am putting an ls engine and trans out of a '15 Silverado in my '63 Pontiac. I plan to use the compressor, condenser, evaporator and hoses off of the truck because the charge seems to be quite critical with a variable displacement compressor. Is there a compressor that will fit on that engine with a mechanical variable displacement or is there some way to modify the existing compressor to mechanical?
Thanks.

[rustystuff]

I would ask over at LS1tech.com forums and see if an earlier LS engine compressor has the same mounting style. LS has been around since 1997 so the earlier compressors may be fixed displacement, I know the previous gen LT1 engines are.