I bought a new condensor locally for my 71 GS, and it's way flimsier than the original. In fact, the fins are so thin they'll easily bend just with finger pressure. I know there are various aftermarket condensors available and I'm wondering which ones are of quality comparable to the original. Thanks.
It's hard, if not impossible, to find quality to match 1971 OEM parts these days. Check with Classic Auto Air in Tampa, Fl. http://www.classicautoair.com/ They have a condenser for your 71 (70-72 A Body) that I've heard a lot of really good feedback about. I've not personally used one. It's "supposed" to be a Parallel Flow condenser suitable for R134A. (I think it's actually a modified cross flow condenser). Regardless, it appears to be a VERY good, quality unit and should work well with either R12 or R134a in your 71.
