Better read this. I think on a normal application as long as it itsn't too crazy you will be fine. But on a high hp motor you may want to go to the select brand of melling. This is related to the m55 pumps most people use as stock replacements. I had ordered 2 and thankfully I saw that post before engine went in. Sure enough I measured the new style to the old m55 I had and there was a bid difference in the mounting flange. I reordered with a melling select 10550 which accepts our diameter pickup tube. Just though this would be good information for everyone to know and maybe avoid a potential problem.

http://forums.godragracing.com/viewt...6095&highlight

 

Hmmm...Hope mine was pre design change. Stupid cheap companies. One simple cost savings change can cost someone a motor.

 

Ouch! I put an M55 on my motor recently. Have not got the engine back in the car yet but hopefully I won't have any breakage issue with it.

 

thanks for the info!
you saved me a huge headache!
if you want a std volume melling select pump with 3/4"
pickup part# mel-10554
just add the high pressure spring.

 

the select standard volume 5/8 pump is pt- 10553
This is for high performance race motors (summit 72.00)

the cheap stock replacement pumps are (16.00)
m-55
m-55a

 

There have been big threads about this in the Corvette community. Good to bring this to attention around here, if people did not already know.

 

Here is a good photo of the m55 vs. the 15503.



The m55 looks pretty dinky to me.

 

I use a Miloden.

 

Just get the melling select series and you should be good.

 

Glad I went with Moroso. Thanks for the post. I'll remember it for future referance.

Frank

 

http://store.summitracing.com/partde...5&autoview=sku

Here is the 10550 pump, it claims to be a high volume. Will this cause pan sucked dry problems which would be even worse than breakage in a fresh 355 LE2?

Here is the standard volume pump 10553:
http://store.summitracing.com/partde...5&autoview=sku

 

http://store.summitracing.com/partde...5&autoview=sku

That's the high pressure Select pump. I think you could get the white spring for less than $25 though.

They have two different HV pumps as well. One is 10% more and one is 25% more. The standard M55HV is 25% more volume. What do you think about running the 10% more volume with a stock pan? Could get that and install the white spring for higher pressure. It comes with the hardened driveshaft and anti-cavitation capable. It does note that the anti-cavitation does slightly reduce oil pressure at idle.

 

So where can the white spring be purchased?

 

GM dealerships AFAIK. Someone said Autozone was carrying it, but that may just be a rumor.

 

...where you buy your GM parts (like the dealer)...