Waterman pump question

I am running an old LF K8 HH retro blower at 50% at present but will be going to a PSI D screw blower for NHRA TAFC soon after. I can get a pump w/ either .750 or .850 gears and have to pick by Saturday.

Sid told me .800 for the roots and screw or .750 for the screw. So which should I choose, My understanding is more fuel pressure is always a good thing but I don't want to screw up my roots blower either and I'm not sure what the larger gear will do with the screw blower.

Any help?

Thanks and happy new year everyone,
Trevor Sherwood
616-642-6009
Soldierboy0098@yahoo.com

 

If your starting with the Roots....DON'T put the 750 on, won't be enough! Ya can always change the gears later