Brought a 91 mustang gt (302HO) about a month or two ago. Car runs good when cold but when it warms up (about 30mins of driving) the oil pressure starts to drop. When driving at a steady speed the oil pressure will maintain its self (but the tempature guage goes up almost to L on NORMAL and fluctuates back in forth to the M AND L ) when I come to a stoplight or any complete stops the oil pressure drops way below the red line, and goes back up when I accelerate. It also seem like my car loses power when this occurs. HELP PLEASE I'm tired of dealing with it.