After receiving so much helpful advice on this forum, I hope this will be of use to some of you.
I was looking for an alternative to spending over $200 for a new heater core and stumbled across a core that has similar dimensions to the one that inhabits our non-A/C cars. It is from a VW Jetta and is made by VISTA-PRO Part # 399901. Total cost was around $60, so I gambled and ordered it online.
You can see the angle of the inlet/outlet pipes is different, so some modifications to the heater matrix box needed to be made, specifically, to the hole on the top left side.
Using a Dremel, the plastic can be cut away from this:
To this:
With that done, the VW heater core drops in pretty easily. You will just need to seal the ends with some foam tape.
It all works pretty well and is a lot cheaper than buying a new core, or trying to get your hands on seals to fix an old, leaky one.
