oil pump?

my 88 hb is making a dry knock in the top end and putters when shifted. the motor ha sjust been built from the ground up with new parts. and is pushing about 200 hp so i dont know if this is just the oil pump or not. idont want to have to rebuild the motor again but its like 400 bucks to take it somewhere. if anybody has any ideas on if it might be something else pleas tell me soon. cause i might just scrap the motor if it is the pump.