i am installing an F54 block and P90a head in place of the original 240z motor. My question is the oil pump i am using did not come with the motor. some people say i need a oil pump from a turbo to lift the hydraulic lifter on a P90a head. is it true? is there any way i can differentiate the oil pump for hydraulic lifter and oil pump for solid lifters?

You probably would be best with a higher volume pump than the stock one. If you can find someone close by that knows their "stuff", you can have the stock pump shimmed to give you the increased volume and pressure.

If nothing else, MSA has the higher volume pumps avaliable for about 70 bucks. They offer 15-20% higher volume, so that should do the trick, and it is a new pump so you would not have to worry about it for a long time......I think the higher volume pumps they sell may actually be a pump designed for the ZX.

My choice would be the new pump from MSA, cheap insurance.....