1993 Dodge D350 cummins engine oil pressure gauge drops when you excelerate When you let off the excelerator the oil pressure goes back up Engine runs fine?

first off, has it been doing it ever since you got it...or did it just all of a sudden start happening... if it's a new problem, I'd have the oil pressure checked...also, is it charging ok(gauges)... also, the sending unit may be faulty at high oil pressures... got good oil? I recommend 20w-50 with LUCAS additive for just about any motor, especially a diesel....good luck:)