I ordered a stock pump from advance auto, and installed it, well it destroyed my motor, I took it apart to find that the pump WAS the HV pump, so I called advance auto and they told me this was the stock replacement pump, but they could get me the other, so make sure your buying what you need , not what they tell you it is.These were both Melling pumps.
I bought a Stock LT1 motor out of a 94 Caprice Classic, from the original owner, the guy told me it was never apart, but when I pulled the oilpump, it was the HV pump with the 5/8 pickup.

 

My new 355 LE2 engine has R&M bearing clearances of .0025". I was told that this is a tad looser than GM spec but it is more desirable for high revving performance engines. I will be using the stock LT1 pan.

I want to ensure that that I get the right oil pump the first time since its a PITA to replace with then engine in the car.

I currently have the melling 10554 standard flow select pump w/ the GM white spring installed on the engine.

I have gotten mixed feedback on what pump to run. Some say the stock flow will be fine and others say to use the Melling 10552 10% higher flow select pump since my clearances are a tad looser.

I am totally confused as to what to do here, I have the brand new 10554 already installed but I am second guessing myself.

 

Damn it.... my order from Summit just shipped! Oh well... Im sure there will be no problems with the 10552.

-B

 

I can understand that. Get the pump your machinist recommends.
You should probably do some research about HV pumps and stock oil pans. If you're going to spend the money on all what you mentioned you should also spend a few extra hundred dollars on a pan with baffles and trap doors.

 

Anyone got some after market oil pan part #'s for a LT1? I have looked at Jegs and Summit???

 

Thats what I am going to go with. I had the M155 but it came with a note saying that it wasn't good to use on high performance engines and to use their select brand which would be the 10554.

 

Canton #15-242T pan for direct bolt-in, '93-97 F-Bodies.



http://www.cantonracingproducts.com/...road_race.html

 

The 10554 is much more robust than the dinky 155 from what I have seen.
I am going with that with the GM white spring. Its bolted up so no going back now. God I hope the pressure is acceptable with thos .0026 clearances.

 

So which is best it shows 2 types for Fbody? 15-244 and the shallow 15-246. One says it needs to be notched for the steering linkage. I am trying to get a good pan for 383 with street/strip manner. I know the HV pump will be the one I want, but only if the pan works in conjunction with it.

Talk about confusing looking web page. I am going to have to call them it looks like.

 

I don't think that a .025 bearing clearance is anything a stock volume couldnt handle. That is within spec.

 

I just put a Mellings 10554 pump standard volume and pressure on my stock rebuild. I cranked the motor over a few times before the first start, and the pressure went up to about 75LB on the stock guage. After starting the motor and getting it warmed up during the first stages of braking the motor in the pressure stayed between 75 and 80LB. I think that 70-80lbs on a fresh motor is probably normal with a standard pressure spring. After warming the motor up I changed the oil and filter, and took the car for a short drive. The motor had about 70lb during crusing. I went WOT a few times in 3rd gear to help seat the rings and the pressure went up to 80psi.

 

I'm running a Milodon 30909, no provision for an oil level sensor though (I check my oil frequently enough that I don't need one though).

Needs a slight bit of clearancing for the knock sensor, no big deal though.

I also run that pan with a rear baffle to prevent oil from whipping up the back of the pan.

 

#15-244 pan for pre-80 blocks with left side dipstick.
You don't want that one.

The #15-246 is the one that requires the notch/etc...
You don't want that one.

You want:
#15-242T pan for direct bolt-in, '93-97 F-Bodies.

 

Just make sure you fill the oil pan with water 1st and set it on some newpaper to see if it leaks. My 1st pan leaked and my engine builder sent it back. The 2nd pan was great!

-B

 

Melling lists several bolt-on pickup screens for their select pumps (10554, 10552, 10550, etc...)

I'm not sure which to order....

They list part # 12557 for 7" deep pans, part # 12558 for 7 1/2" deep pans, and part # 12559 for 8" deep pans. Which is the best match for a stock pan?

Anyone know?