I just tossed a new carb(edelbrock #1411), camshaft(edelbrock #2162), intake manifold(edelbrock #2161) on my truck. I also had the valves done, so now it runs awesome, but there's a problem. Before the "surgery", my oil pressure gauge would read 30-45 psi at idle, and 45-60 psi on the freeway, depending upon how much oil was in the pan at the time. Now, it reads 5psi at idle, and it will barely break 30psi on the freeway. There is plenty of oil in the pan, and I don't have an oil cooler. The dipstick reads full everytime I check it. Could the sending unit be malfunctioning, or should I pull the pan and check the pump pickup?
If you didn't do anything to the bottom end, the oil pressure should be the same as it was before. I'd suspect the sending unit at this point. Is it mechanical or electric? If electric, try replacing the sender and gauge with a mechanical unit and see what readings you get. If mechanical, try another sending unit. Don't use pipe sealer or tape on any electrical sending unit...
sometimes when doing a valve job on an older engine the new compression can create new/more pressure on the bearings causing them to ware extreamly fast considering that they may have been worn or slighty lose pryor to the valve job, oil pressure is created by the bearings, when bearings are at the correct tolerance then good pressure and the looser they get the lower the pressure
And that would be why the long time rule of thumb has been "You can do the bottom without doing the top but not the top without doing the bottom." If it's worn much it will start knocking the bottom out of it.
