Newly Built 383 Stroker w/Quadrajet

[77cruiser]

With holes in the plates you're passing more air through the venturis & increasing chance for nozzle drip. Either way you are going to need to richen the idle circuit.

[Frank400]

what Cruiser said.

    Holley guys can get away with drilling the plates because their boosters are not as sensitive as Q-jets. 
     

[ykf7b0]

First gotta ask how much initial timing do you have?
[/quote
I've now got her idling but I'm getting a surge.  Initial timing is at 17.

[ykf7b0]

With holes in the plates you're passing more air through the venturis & increasing chance for nozzle drip. Either way you are going to need to richen the idle circuit.

I have Cliff's book and I read why but I'm unclear of how to richen the idle circuit.  Could you explain it?

[ykf7b0]

I have Cliff's book and I read why but I'm unclear of how to richen the idle circuit.  Could you explain it?

Please disregard.  I found the info in Ch. 6.  I must admit I'm nervous about this mod and messing up a decent carb. 

[77cruiser]

Once you get the idle tubes out it's a piece of cake. Do you have a set of small numbered drill bits?

[ykf7b0]

Once you get the idle tubes out it's a piece of cake. Do you have a set of small numbered drill bits?

No.  Where did you get yours?  One other question if I may?  Would it be possible to cure this idle problem by backing out the idle mixture screws a little?  Thanks!

[77cruiser]

Got mine here.
https://www.mcmaster.com/#drill-bits/=1994gik

This looks to be a good source too.
http://www.micromark.com/mini-hand-tools/drill-bits-pin-vises
http://www.micromark.com/20-piece-Drill-Bit-Set-41-60
http://www.micromark.com/20-piece-Micro-Size-Drill-Bit-Set-with-Index-61-80

You'll need to buy both sets to get the range you need, unless someone else has a better source.

[ykf7b0]

Thanks! 

[ykf7b0]

To my surprise I was able to get the quadrajet to idle consistently by adjusting the idle mixture screws.  Later on and after the total break in is complete I will really get into the secondaries and see how it goes.

[Hotrodssnova]

Drilling the plates could bend the throttle shaft if not careful.  All the quadrajets I have seen, maybe 10, have had the body and top cover already set up with the bypass air channels cast in and open. The only thing you really need to do is pull the baseplate and drill the 2 holes out in the proper spot. I would refer to which recipe you are using, and start out on the smaller side of the hole. Once you do this, you could go larger if needed without pulling the base plate. 

[Hillbillyenginering]

I bought one set of my drill bits from Granger. Then hobby town for the smaller ones. Fastenal and Tacoma screw when I'm looking for exact sizes.

[Cliff Ruggles]

The factory set-up on that carb would not delivery nearly enough idle fuel for that engine combination, even if you thru a ton of timing at it at idle speed it wouldn't have enough.  Take a gander into the carb when it's idling as see if there is any fuel coming off the boosters (nozzle drip), and NEVER drill the throttle plates for bypass air especially from below with the baseplate still on the carburetor......Cliff

[ykf7b0]

To my surprise I was able to get the quadrajet to idle consistently by adjusting the idle mixture screws.  Later on and after the total break in is complete I will really get into the secondaries and see how it goes.

Along with the idle issue resolved this engine is everything I had hoped for.  Good vacuum for power brakes,  not too lopey of a cam to run a/c, and runs very strong.   Thanks to all for the recommendations and your sharing of experiences!