I think at Classicparts and everyone else that sells repro parts they are the same. But what about original? I picked up a set with the left side with a 2” diameter and the right side 1.75”. I’ve heard both answers and just trying to get some clarity. In the 70’s I pulled mine out of a car in the junkyard and used the JC Whitney heater. But that’s gone and replaced with a rebuilt fresh air heater.
Darren Current Project - 1950 3100 5 Window with a rebuilt 216 and 3 speed trans