Here's Morosos answer to HV oil punp/stock pan combination...
 

Ok...I put a Moroso high volume pump/pick-up assembly on the new 355...With a Moroso louvered windage tray replaceing the stock tray. I opted to go with a new/stock 5 quart pan.
After reading all the threads about HV pumps sucking a stock pan dry, I called Moroso to get their thoughts.
Their tech department instructed me to add an extra quart of oil in my stock pan. My obvious question was..."What about windage"? They told me that the extra oil won't hurt anything because I'm using a windage tray!?
This is straight from Moroso, folks. My concern is, even with a tray, won't an extra quart put the oil level up into the crank?

Frank
CPT

Sounds like a band-aid fix to me. I wouldn't do it personally.

I think if I was in your situation, I'd either replace the pump with a standard volume pump...or else buy an aftermarket pan.

On a side note, I was thinking of buying one of those Moroso louvered windage trays too...how do you like yours? Did it just fit directly in place of the stock one with no modifications?

I ended up going with the 10554 pan which is a stock volume select pump. For added protection you add the GM white spring for added pressure.

Well i don't like the idea of the extra oil and think it could make the problem worst.As far as a high volume pump with a stock pan it should not be a problem if your only drag racing.Your only in the throttle for less than 12 seconds so it should not be a problem.I have a couple freinds running high volume pumps with stock pans who have never had a problem,but if you road race or do any auto cross events then it would be a bad idea but it should be fine if you are just drag racing.

I have a milidon pan that takes 6 quarts or thats what they say. If I put all 6 in my oil pressure drops at WOT. I run it right about 5.5 maybe a tad less and have zero problems. I couldnt imagine a stock pan holding 6 quarts.

The streets are littered with engine parts of some people that thought the same thing. Maybe a little dramatic :D , but I've seen too many oil pressure problem threads with stock pan and HV pump to be comfortable with it. Especially, when the stock pump and white spring will do fine. :)

Fill a pan with measured volume of water and see where 5-6 quarts puts the level and then measure how far below the rail the rotating assembly reaches and compare. Consider some oil will always be in the topend.

And oil filter.

I just went with a pan with big kick outs at the bottom its 8qt. I think

I don't see the stock pan holding 5 qts of oil......considerint the filter will hold some but still....not much room in a stock pan.

Frank If you have a k-member then I would get a pan.....I just got one for a 89 iroc....works fine

I'm checking into both options...Swapping to a stock volume pump, or 6-7 quart pan. I used a standard volume Moroso pump on the 386 I built for our '70 Camaro, with a 7 quart pan. It's never had any oiling issues. High volume pumps usually rob HP.
Yes, with my k-member, I could put just about any pan on it that I wanted to. I may go with the same combo that's on the '70. My other option is the new Moroso 5.5 qt. LT1race pan. http://www.moroso.com/catalog/images...oducts.pdf.pdf

I have one other question about this whole thing...If people are "sucking their pans dry" with a HV pump, has anyone seen a "low oil" light come on? Obviously you would have to if you had no oil in the pan, right?

Frank
CPT

I still fail to understand why people are so fascinated with HV pumps.
Fact: on a motor with stock clearances, they have no benefit.
Fact: they rob hp.
Fact: with a stock 4th gen oil pan, they can, and do, cause oil starvation and have destroyed a significant number of motors in so doing. If you don't believe this, do a search and will see many tales of woe from credible people (like me) who learned this lesson the hard way. Mine cost me a short block with a $3,000 rotating assembly.

Get over the HV pump idea. If you MUST use one, for some reason, only do so with an aftermarket pan. Running an additional quart might help, but it will cause even more hp loss. And will it help enough? Do you want to be the guy who finds out that it will not?

Rich

Ok...How about this pump? Summit sells the Melling M55A with the pick-up welded on it for $45. http://store.summitracing.com/partde...5&autoview=sku
The M55A is listed as a "standard volume", "high pressure" pump.

Frank
CPT

Thats the one the I'm using on my LE3 355, but I'm using the TPIS oil pan much cheaper in my opinion.

Would the Melling 10% HV pump be a safe compromise on the stock pan? Most HV pumps that people are having the starvation issues are 25% HV. Would that along with the GM HP spring be good insurance for a high mileage engine that may have slightly lower pressure due to the mileage/wear?

I'm running the Moroso 6qt oil pan and only putting 4 1/2 quarts in it plus one for the oil filter. I have the high pressure pump and the wire mesh windage screen. Has been working just fine for me. :)