Oil Pump Decision

[patmckinneyracing]

Need help making a decision on what oil pump to use.

After pulling my motor apart, turns out that I don't have a regular "low buck" melling oil pump. Turns out my father had an M55HV or high volume pump put in.

When I bought all my parts a couple months ago, I thought I had a cheap oil pump in there so I bought a Milodon high pressure/standard volume pump. So which do I use:

1.) Melling M55HV high volume pump (used)
2.) Milodon High pressure/standard volume pump (new)

Let me know if you need further specs on my setup.

 

[oldtinsmith]

I would check side clearance on the gears, check the cover clearance, and check to see if the cover is flat. All this is free!
If all checks out, I,d reuse it.

Doug

 

[megaladon6]

personally, i don't like high pressure.
if you are not running large bearing clearances or an oil cooler you are fine with standard volume. but if you have an oil cooler or 25+ bearing clearances, run high volume.
like^he said, if the old one is good...

 

[Bonnewagon]

I have allways used the Melling high volume 60 psi pumps on all my Pontiac motors 301 to 400 ci. I get great pressure at idle and no unusual wear on the distributor drive gear.

 

[chevy2480]

I would not use the milodon i would go with the m55hv. I used the same milodon in My 406sbc the death of that motor was that oil pump. If you look at the passage the oil pickup tube goes in the little plug in that passage fell out thus trashing my crank and a few rods in just seconds.

 

[patmckinneyracing]

My bearing tolerances are definately not going to be 25+. I found that the reason my oil pressure went to hell in a basket was because my front crank journal has almost .015 thousandths worth a grooves. I plan on finding another .010/.010 crank to replace my current one.

From my experience with this melling high volume oil pump, it never sucked the pan dry as some myths go. The Milodon oil pump is nothing more than the older z28 302 oil pump.

The reason I brought this topic is because while the high volume pump may have saved my motor when it overheated, it may be why the journals on my crank are so worn. Looking for as much advice as possible on this topic.

My father tack welded the pickup tube to the melling pump and I'm running a 5 quart pan.