So basically I'm stuck buying a HC heater.
I installed an old escort heater core and a fan I bought from lowes in my old boat. I never had a problem over five years of use. The thing is, I don't want to have to go through all of that again, I just want to purchase one and install it.
If the connections to the core are the problem, I'll probably just weld on some reinforcement prior to installing it. Downside to this little customizing will more than likely mean no warranty.
It sure would be nice if they just built the thing to last in the first place.