'77 A/C retrofit

[mike357]

I'm working on a new to me '77. I have changed the front drive over to the serpentine system from a '94. Now I want to go one step forward and change the a/c over to the later model using the pancake compressor.

I was wanting to change everything to the late model stuff. Condenser, evap core, hoses, dryer everything. Has anyone done this and what issues have you faced?

TIA

[Captkaos]

The condenser is going to be specific to your truck, just get a new one as it will fit, the one from the donor won't.  Same goes for the Evaporator and the accumulator.  Just get a new one for your year.
As for hoses, the ones on the 94 should fit as the Pancake (R4 I am assuming) was already used on these trucks up until 1991.  If the system has been open, definitely replace the accumulator and replace the expansion tube also.

[mike357]

Ok, I was planning on buying everything new. I just figured if I got everything for the same year system I was guaranteed a fit. I didn't know if the hoses that fit the compressor from '94 would fit the accumulator from '77. I didn't know if they went metric or if everything is SAE.

[Captkaos]

You have to buy the condensor, accumulator and the evaporator for the truck not the year of the donor.  The core support is drastically different on the 73-87 vs the 88-98 as is the firewall and associated parts.  buying them for you year will guarantee they will fit you truck by simply bolting them in place.