oil pressure...sending unit or gauge

[judd]

i have an 83 sierra classic 4x4 with a transplanted 350. i put the motor in about 2 months ago, used. upon install i installed a new oil pump, pickup tube and screen. i have put about 300 miles on it. since the new engine i watch the gauges religiously. saturday i get on the highway, look down and see 0 oil pressure. jumped the grass and access road and pulled in a parking lot. checked the level and about a quart low. drove across the street to wal-mart and got a quart of oil. pulled the passenger side valve cover and the rockers are getting oil good. i can see oil running in the head through the fill hole and the drivers side so i chock it up to bad gauge or sending unit. drove another 50 miles that day and the next no problems or noises. monday i fire it up and it reads about 5 psi and bout 10 seconds later back to zero, no rise with a rev-up.

my question is, what has everyone experienced as the most problemactic part in this system? and is there a stock mechinical sending unit and gauge that will fit in the proper location in my dash?

sorry for the long paragraph

[GreaseDog]

stock gauges are notorious for being inaccurate. put a mechanical test gauge on it and see where it really reads.

[judd]

when they do go bad is it normal for them to read way low(around 7 or so) it was reading great up till this weekend(45-55)

[dave89iroc]

put a mechanical gauge on it, make sure you have good pressure

then, unplug the wire at the sender, go look at the gauge, should be pegged(either high or low), then go ground the wire , the gauge should be pegged the other way, if so, get a new sender(if your oil pressure is good)