273 overheating after new timing chain set and waterpump

Dont trade your pump in as a core. Hang onto it. ...
Your old one may come in handy for..Rebuild kit?
2448315 (No A/C) rebuild kit! impeller, shaft, seals, etc.....
NOS MOPAR 2421376 63-68 W/ 273, 318, 340 CID WATER PUMP REP PKG W/ 2448315 PUMP | eBay