Early Slant Six A/C Success
A couple questions:
1. Why would the engine to firewall matter? Did the Nostalgia brackets have something that went all the way to the firewall?
2. Your AC belt appears to run on an "inner pulley", that mounts inside the damper. Did your engine already have that? I think the factory installed it only on AC cars. You must remove the damper to install it.
There are several threads on the Slant Six forum about AC compressor mounting. One option is a ~79 Volare/Aspen factory brackets for a Sanden (I have). I noticed you don't have power steering. I am currently working on custom brackets that mount to that p.s. pad on the block. Syed did similar on a 64 Valiant.