AC from 84 into 76?

[gchemist]

Get a catalogue from www.lmctruck.com. You'll find the difference in A/C parts. You can swap it in.
You can use the stock A/C setup. Adaptors are available to properly route the hoses for use.
77 LS install http://www.hotrodlane.cc/77chevytruck/77chevy.htm

You can also use a early 90's style compressor and bracket.
http://www.maliburacing.com/forum/vi...hp?=34&t=79059

I would use the LS compressor. It is more efficient and will last longer.

A new condensor should be a crossflow type. If you buy one, check that it's a true cross flow for R134.