I have recently assembled and installed a 351 c 4v. Mods include forged pistons and rods, crane cam kit, crane hydraulic lifters, crane roller rockers, hardened push rods, push rod guide plates, high volume oil pump. to mention a few. Well I'm having an oil pressure problem the engine has been started a few times and driven around the block once. At first I thought it was a faulty sending unit but it's not. At cold startup it has about 10 psi but as it warms up it drops to 0. At no time is there any oil at the rocker assemblies. I have removed the pump twice and checked it out, no problems found. When I remove the distributor and turn the pump with a drill it is moving oil because when I stop I can hear oil draining back to the pan. Any input appreciated.