The pressure spikes are inherent to the larger fuel lobes. The orifice in the pump simply cannot return enough fuel back out of the piston bore and the fuel backs up and causes the pressure to go high. I discovered it on road race applications years ago. Causes stumbling at light throttle high rpm mid corner. Have since gone away from the 32% and 38% lobes. You can still max out lt4 injectors with a 27% lobe and the pressure will only spike to upper 3000's.