Oil pressure under hard acceleration????

I have an 89 hatchback lx with a 331 stroker engine approx 400hp. You can look at signature for all the parts used but i noticed last night at the drag strip that under hard acceleration once i hit 3rd gear that the oil pressure gauge starts to act funny. In 1st and second i have 60psi oil pressure at WOT. But once i hit 3rd gear the oil pressure starts to drop off and then hitting 4th the oil pressure gauge starts to bouce between 10-40psi of pressure. The oil is topped up full! Now, i am running the stock oil pump cause i have tried both a high pressure and high volume pumps and did not like how they worked. I am running the stock oil pan and im wondering if the engine is sucking the oil pan dry or if the oil is running up the back of the pan away from the sump?

Is the oil pan too small?

Or do i need baffles?

Anyone have a problem like this???

Thanks
Dan

No i have an autometer electric gauge installed. But i made a few phone calls today and found out some people are having trouble with the sending unit for this gauge. So i going to install a mechanical gauge on there to test it out.

Maybe its just the sending unit?