oil pressure?

ive got a 97 1500 350 5.7L and its broke again. ive got new plugs n wires, new dist., new brake booster, new water pump, new starter and battery, nwe alternator, new IAC. ran like a champ til the other day. oil pressure guage goes up to 60 while drivin and drops to 20 while idle. startin the truck, cold or hot, it lags and sometimes i need to give it gas for it to catch if it wont start on its own like it does when you change the oi and wait for the pressure to build up. sometimes itll turn but the rpms are maybe 1 rev/second? the oil presure is so low and as soon as i give it gas it picks up and drives fine. i dont know if its the switch that needs replacing or the pump or what. yall got any ideas?

Welcome Aboard!

Low/incorrect idle may be due to a dirty idle air control.