Helper pump advice - please

Run a "push/pull" ,system,with similar H.P. Same style pump,mechanical. Upgraded to A/N no 8 line,ran a old school Holley red,rated at 7 psi,84 g.p.h. No return line,though.Worked like a champ,3 year's weekend fun,Friday runner/ Sat nite special. Hope this helps. No regulator,intil N2O,came along.