Jets for my 440 6pk

[kelly]

I just got new Holley carbs for my 6 pack set up. I have a 9-1 comp, 30 over and a 6pk hydraulic cam.
Motor has been balanced. I'm new to the Holley 6 pack system and not sure what would be the best Jets to put into them. Any help will be good.

Thanks

 

[Meep-Meep]

Those things are a PITA because to jet the center carb you need to pull it all apart. There is a method to the madness to remove the carbs by which flare fitting to loosen to get to the bolts. Then you want to start the flare fittings before you bolt the carbs down. Assuming you have the factory carbs and metering blocks, you will probably start with 64's in the center and something big like 90's in the outboards. The factory metering plates are stagger jetted and I recommend going with the billet metering plates that accept the regular Holley jets. Note: The metering plate orifice size does not cross over to the jet number. I put 89 and 91 jets (if I recall) in the billet plates and it's not terrible but also realize I'm not done. A chassis dyno or O2 sensor is a MUST! Have fun and good luck.

 

[440+6]

Those things are a PITA because to jet the center carb you need to pull it all apart. There is a method to the madness to remove the carbs by which flare fitting to loosen to get to the bolts. Then you want to start the flare fittings before you bolt the carbs down. Assuming you have the factory carbs and metering blocks, you will probably start with 64's in the center and something big like 90's in the outboards. The factory metering plates are stagger jetted and I recommend going with the billet metering plates that accept the regular Holley jets. Note: The metering plate orifice size does not cross over to the jet number. I put 89 and 91 jets (if I recall) in the billet plates and it's not terrible but also realize I'm not done. A chassis dyno or O2 sensor is a MUST! Have fun and good luck.

X2 on what Meep said. I am looking into O2 sensors now and billet plates, I have drilled metering plates now and it runs pretty strong but I just can't leave stuff alone.

 

[kelly]

Thanks for the info.

 

[lewtot184]

if the engine is near stock use 64's in the center carb. leave the main metering orifices in the end carbs alone, open up the idle feed restriction in the end carbs to .038", back out the end carb mixture screws 3/4 turn from closed, keep the yellow springs in the diaphragms.

when removing the carbs from the manifold never touch the fuel lines at the carbs once they've sealed. to take the back carb off untighten the end carb fuel line at the t tee. to remove the center carb take off the back carb and untightened the horizontal fuel line that comes off the front carb tee. this will leave the fuel line up to the center carb and tee connected to the carb. removing the front requires removing the back and center carb plus untightened the fuel line from the pump. this will leave the horizontal/tee and tee to carb line attached to front carb. re-install in reverse order. clear as mud?

another thing; the carbs will never perform well with one of the newer single diaphragm/2 valve mechanical pumps.