273 overheating after new timing chain set and waterpump

Theres 2 types of impellers. 6 blade and 8 blade.

The 8 blade impellers are for non A/C cars because of a larger diameter water pump pulley that turns the pump slower. The 2 more blades is to increase the coolent volume because of the larger and slower turning pulley..

The 6 blade impeller pump is for cars with A/C as the water pump pulley is a smaller diameter and turns the pump faster at the same given engine RPM.

Metal or plastic bladed pump does not matter. What matters is you have a pump with the right number of blades or fins for the given pulley diameter and its subsequent pulley RPM.

Putting a non A/C water pump (8 blade) on an A/C pulley equipped car helps increase coolent flow. Putting an A/C water pump (6 blade) on a non A/C pulley equipped car does the complete opposite and slows the coolent flow down further.

Hope this helps.
Matt