Fuel pressure is dropping at the track and I was only running 1/8mile. Still a fresh build, it’s a 493 with a pro form 850. Has a Holley black pump dead headed, 3/8 feed line, with a 3/8 sending unit out of the stock tank. I set the regulator to 7psi and it’s down to 3 while I’m still in second gear. Pump is ground on the frame, seems like a good ground, power out of a fuse box I installed then to a 20amp toggle switch then runs to pump. What am I missing?