Wanna see a 585?

Need to measure squish to figure plan, gots to be careful taking to much off base due to impulse locale.
B6-AAF2-FB-87-B7-4-E55-A8-CA-FB6995-C7-F6-DB.jpg

Block/eliminate the factory impulse setup and rig an external line from a barb on the crankcase to the pump cover.