Holley 750 dp setup

[BlueOval Ralph]

As Blueoval Ralph suggested, I would open up the idle air bleeds .003 to .006 before I drilled the Primary throttle blades.

Note: I DID NOT SAY TO DRILL THE IDLE AIR BLEEDS, BUT OPEN THE IDLE FUEL RESTRICTION GET A LARGER AMOUNT OF FUEL IN THE SYSTEM. Holes in the the throttle blades will not hurt you, infact it has been used in some production carbs.

Originally Posted by Ron Miller

As Blueoval Ralph suggested, I would open up the idle air bleeds .003 to .006 before I drilled the Primary throttle blades. I would rather mix the added air in the idle channel sooner than in the added holes in the throttle blades. Getting the idle mixture correct, you might see a increase in vacuum. Also use a good vacuum gage to adjust all your idle mixture screws. Adjust in park and check in gear. Adjust screws in or out to achieve the highest manifold vacuum. When idle is adjusted correctly their will be a increase in manifold vacuum. You will have to change the power valve. To choose the correct power valve, put into gear, foot break the engine to launch r.p.m. and look at vacuum gage. Example,,,,, if the vacuum reading is 9 to 8", choose a power valve 1.5 under that reading.


Ron