MaSnaka,
As DECOONEY noted, these are old tractor engines, however they do perform, and have almost the perfect range for a street 2400 lb or so COBRA. Do not compare to a high
oil pressure or pressurized cooling system as needed in a Chevy engine.
Optium pressure at idle is around 40 lbs plus a little, warmed up, however 20 lbs and up is fine as long as the 3000rpm range and up gets it into the proper lbs for the wear/miles you have since rebuild, about 50-80 lbs. We never use "spring kits" just to boost pressure to give comfy feelings on pressure in the FE. More depends on the
oil type,
oil pump, filter, and and other oiling system modifications that some performance engine builders do.
grumpy