Finally was able to dyno the motor and this is what I got with the original 2X4 D manifold.
After numerous pulls with the pair of 750 vacuums and re jetting we netted 619hp and 610tq. I bought a pair of 660 centers prepared by Allstate Carb with 76 jets and metering plate squared.
1st pull fouled plugs so dropped the jets to 72 with metering plates unchanged netted 635hp and was still pulling too much fuel.
Ran the carbs to Allstate and Jim immediately changed the metering plates to 72 and opened the hi speed air bleeds. I took a pair of 70 plates with me in case.
This netted 655hp at 6300 and 623tq at 4700.
Changed the primaries to 70 and plates to 70 at 38* timing and made 664hp.
Plugs read perfect and fuel flow where it belongs.
Engine specs described at the top of page.
