That unit is the same as OEM - Copper Tubes with Aluminum fins. A nice copy actually.

Nothing rots an evaporator better than 2 cups of pine needles & oak leaves in the case, kept wet with condensation. It looks like the used evaporator you linked to had about a cup in there with it, based on the corrosion on one end. An aluminum evaporator would be just fine unless you park under...

Well, yeah if you have not had the box out to rebuild it, then your refrigeration system is probably working very well. The kink could be more than 20 years old, and may have been straightened enough right when it happened. Sleeping dogs & all of that - for now. The likelihood of the foam seals ...

You would have to remove the evaporator from the car to anneal the tube. Have you ever had the evaporator out of the car? What sort of shape is it in overall? If the suction hose is OEM & weeping dye, I would replace it. Sounds like you are at a spot where recovering things & replacing a hos...

That Catalina had over 200k on it when I sold it - "that trip" happened on a regular basis. The "Green Hornet" went everywhere, wish I still had it. Green on Green with A/C PS PB. Roll up windows. I bought it barely used from an old man that lost his eyesight. True, regular back ...

At this point the factory suction hose is already suspect because of the weeping dye. It could have a partially collapsed liner. If this was a POA system I would suspect the POA valve. I don't remember much about that model year. Only that 69/70 was a 2 year run before they changed things again. As ...

I am still trying to wrap my head around a 2bbl 389 Pontiac that gets 12 mpg I had a 1970 Catalina with a 400 2bbl that got 18 around town & 24 or so on the highway. With 4 people in it headed from Las Vegas to Salt Lake City at 75 MPH we never stopped for gas. And never went under 75 mph either...

The V7 is a GM variable displacement compressor, with more displacement than many compressors. Oddly enough GM chose to use it in some S10 pickups, and those have ear type mounting - but they are not a direct replacement for a Sanden SD508 - so you would be making brackets. The V7 comes with a 6 rib...

That is a significant leak. You should be able to find one that big with soapy water.

If there is no dye or hits on the sniffer under the hood, you need to check the evaporator. Try the sniffer in the vents inside the car.

Which EFI are you running? 13mpg sounds way off, unless you have a huge cam in it... i had a 455 that got 12mpg with a Quadrajet. Your 2nd gear / 3rd gear test shows the volume issue. Even with road speed & ram air, you still can't produce enough volume. You could swap out to a V7 compressor &am...