holley 600 vac. secondary metering conversion

[gliderider06]

Hi all,
I have a Holley 1850 600cfm vac secondary carb and I bought the secondary metering block conversion so I can change the jets in the rear. What jet size should I start with? is it 12 sizes larger than the fronts? I am running 68 fronts and I put 80 in the rear. It just feels like it is not getting enough fuel. I also did the quick change spring kit, and tried a med/light spring. Float levels are set. just feel like it's starving for fuel
Thanks, Paul

 

[70aarcuda]

8 sizes from the front to rear is what I would use...

you can take the meter plate and look the part number up at holley...and it will give you an equivalent jet size..


[ame]http://www.holley.com/data/Products/Technical/199R8110rev3.pdf[/ame]

 

[crackedback]

Could also be really fat and laying over.

 

[gliderider06]

It was REALLY fat. After looking at the chart, I was supposed to put #69 in block. I dropped it down to #72 and got waaayyyy better. I put a lighter spring in and it got worse again. Bumped it back to a stiffer spring and felt better. I will go and drop jet sizes down to a 70 and see how it does. Just kinda strange that my secondary jets are almost the same as primary #68.
Thanks!