HV vs Std Oil Pump Info

nm9stheham said

Just so I am not confused.... this HV pump is a Mopar Performance HV pump PN4286589-001 on the box, but the pump itself looks to be actually a Melling M72HV; that number is stamped in the casting...... In that case, your info 'splains the heavier spring.

So is it just the MP STD pumps that have a lower spring pressure.... assuming it too is not actually a Melling.....? (And presumably the older stock pump too.)

Click to expand...

We dove into that in January in my how to change a pressure relief spring thread.

Mopar uses the std 55-65 lb spring in both their std and HV pumps. You can buy the high pressure MP spring to get them to 75 psi.

Mellings all come with the 72 psi spring. Mellings does not use the 55-65 psi spring.

Neither Mellings or MP could tell me who made the MP pumps. The MP pumps seem to be a different manufacturer than Mellings, but I could not find anyone in either company that could verify that...

http://www.forabodiesonly.com/mopar/showthread.php?t=301617