I have recently rebuild my 318 adding roller cam and solid lifters. Th heads are cast iron 360 heads with porting and big valves. On top adjustable rockers from Hughes. The oil pan is 7 quarters the oil pump is high volume.
Th eproblem is oil pressure that is around 70 psi cold idling but when i rev it up above 3000 rpms it goes over 120 psi . Engine was puttin 400 Hp on the dyno.
What i already did :
-chacked the pressure with other gauge
-changed oil filter to another one WIX 51085
-changed the oil pump to SEALED POWER 224-4166V
-changed the oil - curently 20W-50 (used to be like that before)
I will appreciate any ideas what to check next

 

Why the 20 / 50 and is it synthetic?

 

Thats a std, pressure pump.... Sounds like the relief valve is stuck in the pump. Just my 2 cents...

But if i under stand your post correctly... You have already replaced the Oil Pump? And the problem continues?
In that case I would try a higher GPM flow rated filter like a 51069R and see if that helps the restriction problem.
And I am with Iowan... Really dont think you need a 50W....

 

for sure, try just 10w/40 in the thing. that 20w/50 isn't what it wants.

 

I would switch to 10-30 maybe. Don't worry about it so much.. A new motor may have some tight clearances.. My 360 Idled around 60psi cold too. Now if you said it had 10 lbs at idle I would be worried