a/c retrofit question

The '63 and early '64 firewalls are the same on the Dart and Valiant. The firewall was changed midway through the '64 model year due to the introduction of the V8.

The early firewall protrudes into the engine compartment. The later firewall is flat to accommodate the V8 rear-mounted distributor.

The early firewall is set up for rod actuated carburetors; the later one for either rod or cable actuation. Rod was used for slant sixes without factory air; cable was used for factory air or any V8.

--Walt Jackson