Hello just found this web site cool. I have a 90 350 and it runs strong. it has 33 lbs @1000 and 65 lbs from 1800 up . tell 4500 to 6200 the oil press slowly drops off to 30 lbs . when i lift of the gas it comes right back up to 65:. stock pan melling m55 pump
I hear 10 lbs is good for every1000rpm . well im coming up short on that end,

 

When you installed the pickup to the pump did you verify that it was fairly parallel to the bottom of the pan? I have seen a couple incidents where there wasn't enough clearance between the pan and the pump to allow the volume of oil that is needed at high rpms.
HTH

 

Im with Chris...

Also,another thing that could be is the pick-up may have fallen off...not likely but has happened before and could cause that.

 

yes pick up was set at 1/4 off the bottom of pan and welded. im going to try ading 1 more quart of oil tomaro and run it agine. ill get back after that has been tryed. thanks for the help. and next week is the first race of the year and i will run it like it is if i have to. this is a home build 600 $motor that wont hurt that bad if it does go. runs 13.20. and has 70 passes on so far.

 

you need a aftermarket pan to hold enough oil nessacary for a high volume pump

 

Exactly, it is not uncommon for a SBC to run the stock pan dry during extended high rpm use. If your excellerating you also have the oil being push back away from the pickup.
A good high capacity after market pan with baffles should solve this problem.

 

Thanks ill get that orderd asap . i did try it with 1 more quart of oil and still droped of but only to 40 psi. but i know better than to run it over full.

 

Good news changed oil and oil fillter . and oil fillter by pass adapter problem fixed.