[Tom Vaught]

I ran across a post from the Dominator Board I used to post on with Tuner and Markaudio from years ago.

The specific Dominator is a 3 circuit carb that was modded back to a 2 circuit carb.
Jeff (the carb guy from the Pontiac board) has done several of the 3 circuit carb to 2 circuit carb conversions. I would recommend him for the conversion as he may have some Pontiac specific mods above and beyond what I am going to post below.

Here is the information:

Hey guys,im setting up a holley 9375 dominator for a friend and doing the 2 cicuit conversion like i did on my 1095 king demon.
This is for a 496 c.i chevy bigblock with afr heads and a 248-256@.050 cam with .695 lift.

My question is this.My 1095 demon has the idle eze feature i installed for idle air.This holley does not.
Should i be drilling throttle blades for some idle air?Or should i try it without them first?

I set a set of 4150 proform blocks and carb as follows for the 2 cicuit conversion:
IAB=.070
HSAB=.026
T-JETS=.063
EMULSION HOLES 1&3=.026
EMULSION HOLES 2&4=BLOCKED
ANGLE CHANNELS=.161
KILL BLEEDS=.028
IFR'S=.036
PRIM PVCR=.089
SEC PVCR=NONE
PRIM PV=3.5
SEC PV=BLOCKED
PRIM JET=85
SEC JET=93
SQUIRTERS=42
PUMPS=50CC
CAMS=YELLOW

This is the recipe i have on my 468 pontiac that works great.Only difference is the idle air. Should i drill throttle blades on this holley since it dont have idle eze feature?

It's been my experience that holes in the plates are only needed if you can't get enough air without over exposing the T-slot.
My Dominator has .040 slot exposed with the blade shut. So, I had to get some air without exposing any more slot.

Remember this info: As related to the transfer slot, everything below the butterflies is fuel, every thing above the butterflies is an air bleed.....as you open the butterflies your adding more fuel but reducing the air...

Personally I would play with the IAB and IFR before drilling any holes in the blades...and maybe open up the TSR if you do drill holes then you may need to adjust (or remove) your "Transfer Slot Restrictor" size....

A few Dominator carbs have a bunch of slot exposed below the blade with the blade 100% closed.
You try to open the blade for curb idle air you expose more slot.
The fix is to leave the blade 95-99% closed (100% will stick) and add curb idle air either by drilling holes through the blades or on race apps by bleeding air through the air filter stud boss.

This specific Dominator needed .040 slot exposed below the blade with the blade shut. .060 holes in the blade were added with good results.

Feed-back from the guy working on the carb:
There is no t-slot exposed with blades 100% shut.
I have the butterflies adjusted to expose .020 t-slot back and front.
I put the carb on yesterday and it did need some more idle air.
I drilled .070 holes in blades and it worked perfect.
Still have only .020 t-slot showing.
The idle screws are out 1 1/4 turn and responsive.

The motor seemed to love the starting recipe i gave the carb as a 2 circuit. All I did was turn out idle screws 1/4 turn and drill blades with .070 holes.

So there you have the post and the info we provided to him.

Tom V.