Oil Pressure problem

Ok, I just rebuilt the top end of my car. PnP heads and intake. Reason I really took it apart cause i got a great deal on the pnp heads and intake and i had a horrible miss and thought it was the valves. Turned out i broke a valve lock and was about to drop a valve. so i guess it was good i took it apart. . But after i got it back together i noticed that when i stomp on the gas, at about 3k my oil pressure starts to drop and by the time its at 5500 rpms its in the red. At idle it usulaly stays about straight up and down. What do u think this could be. I kno the stock gauge sux but its startin to scare me. Some times the oil pressure dont drop that much then sometimes it drops to the red. But I think if i ran it it in the red for a few seconds it would blow up but it still runs great. I dont kno what to do. I think im gonna get me a oil pressure gauge and see what i get with it. Is there a good install article for a electrical oil pressure gauge anywhere. Thx