I have started to clean up the heater that was in my truck when I got it with the idea of re-installing it to extend my driving season. It is a Tropic-Aire model # 2335. The core is shot and even if I got all the leaks soldered I don't trust it with a pressurized system. Has anyone done one of these and know of a modern core that works out? Part # or application?
looks like a variety of heater cores could be used in that case. take it to the parts store and see what fits.
My local radiator shop had a book (a BIG book) full of heater cores with measurements. This doesn't answer your question directly but should result in a new core for your Tropic-Aire if you do some digging. For my Firestone I used the stock core with a SPAL "puller" fan. Before: After: