OK...I've spent all evening looking back through all the old oil pump threads on here.

My new 355 isn't in the car yet, but currently has a Moroso high volume oil pump with a stock pan on it.

I just bought a pump/pick-up assembly from Summit, just to find that it's the "junk" M55A Melling pump.

I also understand that the standard volume pump from Moroso is also the M55 pump.

Supposedly, Melling redesigned the M55 because GM wanted them to. What does GM use this pump on? Is the 12555283 pump actually the M55? If not, what does it resemble? Who makes it?

I'm contimplating the use of Morosos new 5.5 quart LT1 pan (20185) with the current Moroso HV pump.

If I stick with the stock pan, I'd like to find a good quality stock volume pump...That's NOT made by Melling!

Anyone know if Milodon makes their own pumps?

I'm pretty rrestricted to what pan I use because I'm using MAC headers, which come pretty close to the pan.

I also don't want a Canton pan. I've seen too many issues with them not fitting or about them leaking.

Frank
CPT

 

You might want to try the TPIS oil pan for the F-body. I think it's much cheaper and has improved baffling, built in scraper and a special baffle that helps separate excess air from the oil so the engine bearings receive pure oil, not airated. They accommodate high volume oil pumps so you can install and keep the on you had on there.

 

I think they may have changed the number on that I found one on summit
http://store.summitracing.com/partde...5&autoview=sku it's a gm performance part NAL-12555884

 

I was just looking at that GM oil pump on summit. standard volume/high pressure

 

OK...I have found out that, YES, ALL GM pumps are made by Melling. They're all based off the weak M55 casting.

Frank
CPT

 

The 12555283 I used in my car was just like the stock unit with thicker casting. Now, 12555283 has changed to 93442037, so that might be the newer, thinner casting. I don't really know.

 

They are. I was just holding one in my hands yesterday. I've got a pretty good "in" with the local GM dealership/Performance Shop. I had them order every pump GM makes. All were M55 castings.

Frank
CPT

 

so basically this GM Performance oil pumpNAL-12555884 from summit is just a melling casting?? It says high pressure so I guess it has that "white spring" thing in it???

 

Miloden does make an oil pump and pickup. Thats what I am using but I have not installed the engine yet. The pickup comes with a fastener so no welding is required. I like the quality of it but have not tested it yet.