What should idle psi and 2500-3000 rpm psi with a warm engine be.

That sounds normal. There would be specifications for it that you should check, but that sounds pretty normal. The specs probably show a pressure for idle at normal operating temperature, and another figure at a specified engine rpm. Or it may just have one spec at a certain rpm.

60psi cold / 30-45psi warm is ideal. I've seen (with that mileage) 45 cold/ 20 warm and that's acceptable - anything less start thinking about a new oil pump.

how did you clean the gasket off of the head? if you used a sanding disc the grit will eat up the bearings. are you reading pressure with a mechanical gauge? you have replaced all bearings??

6 psi @ 1000 RPM
18 psi @ 2000 RPM
24 psi @ 4000 RPM
this is chevrolet specs on oil pressure in your truck so you are within the range.

describe your idle problem more and i will try and help you with that

One thing you should get checked is the oil pressure.You could have an oil pump that is going out or getting weak.Also depending on how regular you are with your oil changes it is possible that you could have a sticky lifter.The oil pressure at idle should be 4 psi and 25-80 psi at 3k rpm.If it is less than 4 psi at idle do not do the 3k rpm.This is check with a warm engine.(normal operating temp).Hope this helps.Good luck.

First we would need to know when this occurs. Asuming the oil level is at the full mark!. If the pressure goes up during acceleration and down at idle when engine is fully warmed up, then this is normal. An engine requires 10 psi of oil pressure per 1,000 rpm ( ex. 20 psi at 2,000 rpm, 25 psi at 2,500 rpm, and so on ) . If the gauge is moving back and forth erratically at idle , i would say the gauge is bad. If it drops to 0 while accelerating I would say your oil pump is bad. If from time to time it seems to work and other times it seems not to work, I would say the oil pressure sending unit for the gauge is bad. If the pump failed you would start to here a Knocking noise from the engine in a short period of time. Use the above scenario's to narrow down what it may be.

First we would need to know when this occurs. Asuming the oil level is at the full mark!. If the pressure goes up during acceleration and down at idle when engine is fully warmed up, then this is normal. An engine requires 10 psi of oil pressure per 1,000 rpm ( ex. 20 psi at 2,000 rpm, 25 psi at 2,500 rpm, and so on ) . If the gauge is moving back and forth erratically at idle , i would say the gauge is bad. If it drops to 0 while accelerating I would say your oil pump is bad. If from time to time it seems to work and other times it seems not to work, I would say the oil pressure sending unit for the gauge is bad. If the pump failed you would start to here a Knocking noise from the engine in a short period of time. Use the above scenario's to narrow down what it may be.

First off its not a 351W modified. you are confusing two different blocks. its either a 351 windsor or a 351m (modified) and if it is the modified its not that bad. these engines are notorious for having low oil pressure. at idle they can be anywhere between 10 and 40. as long as you gain 10 psi per 1000 rpm its fine. and a pump doesnt drop off as it gets warm. it either works or it doesnt, oil pressure dropping off is a bottom end bearing problem

First we would need to know when this occurs. Asuming the oil level is at the full mark!. If the pressure goes up during acceleration and down at idle when engine is fully warmed up, then this is normal. An engine requires 10 psi of oil pressure per 1,000 rpm ( ex. 20 psi at 2,000 rpm, 25 psi at 2,500 rpm, and so on ) . If the gauge is moving back and forth erratically at idle , i would say the gauge is bad. If it drops to 0 while accelerating I would say your oil pump is bad. If from time to time it seems to work and other times it seems not to work, I would say the oil pressure sending unit for the gauge is bad. If the pump failed you would start to here a Knocking noise from the engine in a short period of time. Use the above scenario's to narrow down what it may be.

May be bad oil pressure sending unit. Best way to check is to connect a mechanical oil pressure guage to engine and check pressures when engine is warm. Should be no lower than 40 psi at idle when warm, no higher than 70 psi at 2000 rpm.

yes that is fine for a stock engine u should have 10 psi for every 1000 rpm and oil grades and weather play a big part on oil pressure