Hello, I want to change the standard oil pump in my 73'Camaro (sbc 400 engine) to mount a high volume oil pump, but now, when I was looking for, I also find the high volume and high pressure oil pump and doubt. Wich of them do you recomend for a slightly modified sbc 400? I only modified the intake and headers, and a edelbrock performer cam.
Can I will have any problem with seals or anything if I buy the high volume and pressure oil pump?

 

Honestly I would use a stock pump

 

You will have no problems with seals no matter which pump you use. Stock pump puts out plenty of volume if your internal clearances (main, rod bearings) are in recommended specification.

Some guys like to run wider clearances, they think it makes more HP. These wider clearanaces leak out oil quicker, so they require higher volume pumps to keep up. Higher volume is generated from bigger gears. Bigger gears take more HP to drive.

Chevy engineers didn't think all this was necessary, so why go thru all that for questionable gains? They did put a higher pressure pump relief spring on higher rpm engines like the Z28 302s. Same pump, just higher pressure for higher rpm. General rule is 10 psi per 1,000 rpm.

Your 400 isn't a high rpm engine, so stock pump is fine. High pressure pump would not be a problem either. It is recommended that you put a spot weld on the pickup tube if you install a new pump to keep it from vibrating off. If you aren't having any problems with your current pump, no reason to rip it out.
.

 

Thanks for the replys, I will mount a standard volume pump.
I bought a 6 quart moroso oil pan in ebay, and when it arrive, (remember that I write from Spain) and mount the oil pan I also want to change the old oil pump, my engine was reconditioned and I don't know if the oil pump was also changed or not.

 

Point of note:
If you are located in a warmer climate, it is common to remove the pressure bypass spring located in the oil filter adapter. After removal, tap it for a regular pipe plug like what is in the back of your block, and plug it. The is the one way valve that allows oil to bypass the filter. It was designed for those folks who tend to neglect oil changes. In performance lingo - dirty oil is going back to the bearings.
If you do bypass it - be responsible like I'm sure we all are. Don't rev a cold engine, change oil and filter as suggested.
Enjoy knowing your good 'ol 400 is well lubed.
adios