Running a 528 wedge, I tried a GPZ years ago, couldn't pull enough to show 3 inch vacuum. Went to a Moroso three vane, got max 10 inch running 50 percent engine speed. I suspect the four vane enhanced Moroso would be ideal, as you can regulate it down and run it fairly slow to get the same results, improving pump life.

Last edited by gregsdart; 12/04/14 08:17 AM.
8..603 156 mph best, 2905 lbs 549, indy 572-13, alky