I would think this one should work New NORS 1974-1979 Chrysler Dodge Plymouth Heater Control Valve 3780701 | eBay
I don`t have a book for your year, the number stamped in the old one would help ID
If you find that wasn`t the short that caused your blown link then I would check the ignition switch connector at the the base of the steering column. Many times they melt and short out and cause problems like yours. I would replace with a fuse link if possible. Also make sure you use the...
Honestly many of the newer made standard replacement pumps are crap. Most made in china india etc. I have not had good luck with them. The summit pump is pricey but much more reliable. I have used the holley pumps with good luck also.