Ease of installation, customer service, the integrated heat/cool coils, the no cable instal using the factory controls, and lastly the fact that I can sit in 100 degree temp in traffic in my 69 for 45 minuits and not one ounce of sweat.
I wanted to give my "Take" on this A/C Unit Un-Debate, I Purchased and Installed Only 1 Unit and probably, never do another.
I never Installed a Vintage Unit, but thought I would give some Info and Pic's. I believe you were Looking for Advice with Both ?
I bought the Classic Auto Air System, And Got All that Keith Mentions Above.
I did a Custom Install and the "Customer Support" from Classic was Over the Top, They even Called me to ask how things were Going after I contacted them.
This was about 5 years ago too, System Options and Parts may have Changed along over the Years.
One thing to Keep in Mind is these Units Do Not take Air From the Outside, Your "Flo Thru Ventilation" will still Operate.
And Take Care while Laying out your "Evaporator Drain Hole" you will be Putting thru the Floor pan. In Keeping your Unit Should be Perpendicular to the Chassis, A Slight Tilt Towards the Drain Hole will be Helpful.
Here is some Info and Pic's, Good Luck with the Unit you Buy !
Timmy from CT
Where is PNW ? "Pacific North West" ?