TomM 25 Report post Posted July 29, 2018 I think I know the answer to this question. I'm in the middle of replacing my heater core. While I'm at it, should I replace the evaporator coil? I haven't had it tested yet but plan to. Even if it passes a pressure test I'm probably better off replacing it, just didn't want to spend the additional $300. Quote Share this post Link to post Share on other sites
det0326 179 Report post Posted July 29, 2018 I replaced mine when restoring the box . The only reason I did tho was they have them now that says they are 134A compatible . Don't know what the difference is tho but I knew I was going to use 134A so I went with the new one. Quote Share this post Link to post Share on other sites
69ShelbyGT350H 61 Report post Posted July 29, 2018 All of my fittings had rusted/corroded so badly I had to cut them off to get the hoses off the core, so mine was a mandatory replacement. Anyway, as I had it out I replaced both the heater core and evaporator so they are both new, and not almost 50 years old. NPD has a new style High Output evaporator for $262.07. Not sure how much better it should perform but living in South Florida, I hope a little better at least. I've not finished my AC install yet, so can't say. Quote Share this post Link to post Share on other sites
1969_Mach1 333 Report post Posted July 29, 2018 If you can afford to replace it, do so. The new evaporator coils that are R134A compatible are designed for more efficient heat transfer which is needed for good operation when using R134A. Quote Share this post Link to post Share on other sites
