Ported 61x cases, ported 64x 760 cylinder, stock head and ignition, Riva Powerbomb carb. Currently at 130p 150m, 115 spring 2.5ns at 20psi popoff. Idle is nice and power seems good right off idle but after 1/2 throttle it struggles to buid RPMs. If I get a little air in the pump it will get past...