low oil pressure

I am responsible for maintaining a 91 S-10 with four wheel drive, automatic and a 4.3 L engine that has the oil light come on at an idle when it is fully warmed up. We switched to 10w-40 oil, but it was not much better. A local mechanic told me to install new rod, main bearings and an oil pump. He said it will be tough getting that engine out to work on it. Should I pull the cab off to get the engine out or can I drop the front drive axle to get the oil pan off?

Tough job in car, you may have to lower the ft axle to get the pan off, check Autozone.com, repair guides.

Maxwedge, thanks for the answer on pulling the pan. Looks like a lot of work. I went to the oil filter in front and removed a plug to install an oil gauge. I read 45 psi cold and 20 hot at an idle. The original gauge is faulty and reads near zero at an idle. I can live with that and not tear it apart.