just a quick question about oil pump.
I have rebuilt my 383 "high output" natural aspirated motor.
but I was maybe a little stupid when ordering a oil pump.
I ordered the high pressure oil pump Melling M55A
But after thinking a little I maybe have to do something about this.
I would be just fine with the stock oil pump?

have heard about twisting pump shaft and other damage caused by this pump!
I have new crank shaft and rod's and cam, my clearance in the motor is 0.002 on rods 0.003 on mains.

I have read that it is possible to change the spring inside the pump, is this recommended job to do?

 

That pump isn't going to damage anything.

It's the replacement for the stock GM pump for LOTS of motors over the years, including the L98.

Whatever stories you've heard about ... all that other stuff, are wrong.

Get a Melling IS-55E drive rod, to do away with the plastic collar.

 

Your pump already has a high pressure spring, no reason to change it.

 

ok.. thanks sofakingdom and Apeiron