Chevy 383 oil pressure problems?

my new Chevy 383 engine seems to not have oil pressure at idle, it goes up while driving but then it falls when coming to a stop, is it my oil pump or some other small problem that might be an easy fix?Chevy 383 oil pressure problems?
Definitly your oil pump you need a high pressure high volume pump on that block trust me you'll get what you need.Chevy 383 oil pressure problems?
Could be an easy, medium or hard problem.





An easy problem could be that you have too-light of an oil or a problem with your oil filter. Try replacing your filter with a different brand, and if you put in full synthetic, don't go with a 5W.





Regarding the filter, I noticed that I lost between 5-8psi when I use Fram filters.





Another easy would be that your oil pressure sender is not reading correctly. Pulling it and doing a read with an external gauge would verify this.





Since it is new, are you sure your oil pickup screen has adequate clearance to the pan?





Not so easy is that your new 383 was built with excessive bearing clearance. This would give you very low pressure at hot-idle. You may also have a stuck bypass in your pump.
I don't know what the 383 is - a bored 350? Anyway, if this is a modified block and components it's possible that the bottom cover of the oil pump, the cover that retains the 2 impeller gears, has too much clearance between the gears and the cover. The gap there is supposed to be something like 10 thousands inch - don't remember for sure. If it's greater than that, oil pressure will drop when decelerating.
if the pressure doesn't drop to zero,and has 10 lbs at idle it should read 40 pounds at 2,000 rpm's if doesn't get to 40 than you might have a pump problem or a bearing clearance problem,and when the oil gets hot it will thin out and lose pressure also.doesn't sound like anything wrong.
A small-block is built to tight tolerances. Every small-block-( of common streetability and longevities)-must comform to specific standards of fit and construction. I suspect your small-block was not carefully constructed and has most likely spun a rod bearing. Dis-assemble it now to root-out the cause. Look closely at the rod bearings and the side clearances,at the crank connections. Look for 'trash' in the crank journals. Bad distributor clearances may do this as well.You may need a 'cam' button to tighten this all up.