Carb info 17058504

[351wpower]

Working on a 66' Pontiac 389 4v Carter AFB engine. Stock except performer intake, Re-curved HEI & dual's.
The Q-jet I'm using is #17058504   2777  BJT 
It has been rebuilt (looks to be from a mass production rebuilder) And has been sitting in a garage for years but it is very clean no rust or pitting so I'm just going to freshen it up a bit with a basic kit, But want to jet it as close to OEM specs (I know they were not used on 389 engines but 68'- ? 400 specs would get me close enough to start)

What's in it now from the rebuilder 73 jets, 41k primary rods, CH secondary rods, F hanger

I know what it has now, And I have seen some stock 400 q-jet set ups. The issue I think is going to be setting up the primary's (close to the specs I want) but using the newer carb I'm not sure about the air bleeds.

Any help would be great Thank you in advance.                 

[Ethan1]

Working on a 66' Pontiac 389 4v Carter AFB engine. Stock except performer intake, Re-curved HEI & dual's.
The Q-jet I'm using is #17058504   2777  BJT 
It has been rebuilt (looks to be from a mass production rebuilder) And has been sitting in a garage for years but it is very clean no rust or pitting so I'm just going to freshen it up a bit with a basic kit, But want to jet it as close to OEM specs (I know they were not used on 389 engines but 68'- ? 400 specs would get me close enough to start)

What's in it now from the rebuilder 73 jets, 41k primary rods, CH secondary rods, F hanger

I know what it has now, And I have seen some stock 400 q-jet set ups. The issue I think is going to be setting up the primary's (close to the specs I want) but using the newer carb I'm not sure about the air bleeds.

Any help would be great Thank you in advance.               

 Welcome to CHP!

 Stock specs for that carb were .071" Primary Jets, 41K Primary Metering Rods, "K" Secondary Hanger and CH Secondary Metering Rods. So, it looks like it has the correct metering rods. These are a basic guideline of these carburetors.

[351wpower]

Thank you that info.

Now the tricky part to bring this carb to or close to factory 69' ish 400 specs (Stock 389 daily cruiser)
And based on the air bleeds from this newer carb. Where should I be on primary jet/rod's

From what little I understand, The air bleeds will dictate my jetting/rod choice. Like on an older pre 75' (I think)
might have run well with 71-73 jet's and 44 pri rod's but the newer design air bleeds I might need 76's and 50+ rod's just to mimic how the older Q-jet performed.
So before I start throwing large jet/rod combos at it Where would I/you start.

Again thank you     

[429bbf]

fwiw my buddy and i took the single main air bleeds out . tapped them with a small punch and hammer from the back side and took a piece of brazing rod and made new ones .i don't remember the sizes. the braze rod fit snug in the hole and then we redrilled the new air bleeds to a much smaller size. we also measured the distance that they stuck out before we removed them to get the right length. i believe we went from appox. .125 down to .070. ran pretty darn good for a couple of redneck mechanics.

[351wpower]

Thanks for the tip.

This is one of those friend of a friend (can you slap this Q-jet on and make it work) deals.
So any surgery or playing around with the main body, Or doing anything that I can't undo I want to stay away from. If this were my Carb I would absolutely do what was needed to make it run right.

For me this Q-jet is the best candidate for the job because its been rebuilt correctly and should be just a jet/rod swap (Should Be)

I thought it would be simply finding out what is in it, then what I want in it (Stock 69' ish Pontiac 400 specs) But the whole different size air bleeds using different jet/rod combos is where I'm lost.

I like the idea of 71-73 jets, 44 rods and CC rods (Specs for an older design Q-jet)
I may need much larger primary jetting/rod's for this newer style Q-jet

Maybe I'm just way over thinking it.
                   

[429bbf]

from my testing your on the right track it seems the single main air bleed carbs all need a bigger jet and rod combo . thats why we down sized the air bleeds and left the j/r combo for our application . it was a basic stock 350 chevy.if cliff chimes in he would know a real close setup for what you are doing. theres also a lot of others that have worked on your same setup fwiw

[351wpower]

Thanks 429bbf,
     
A jet rod combo from Cliff or anyone with a similar set up would be great. Also if It needs a radical change in jet/rod sizes should I be looking at changing the power spring. 

[Ethan1]

Thanks 429bbf,
     
A jet rod combo from Cliff or anyone with a similar set up would be great. Also if It needs a radical change in jet/rod sizes should I be looking at changing the power spring.

 Cliff will see this. Or you could call the shop and tell him the specs of your car, cam and if it's a street/strip car. All info will help.

[351wpower]

Thanks Ethan1,

When ever Cliff gets a chance to see this and can throw me a jet/rod combo, That would be great. No rush on my part and I don't want to bother the man at work. Although I'll be bothering him when I order the parts.

But anyone who has a similar set up I would like to here about there's

I'm working on a 66' Pontiac Bonneville 2dr ht. 389 4v (AFB) auto trans, rear gear not sure, weight 5000 lbs. +/- engine is all stock except for an E-brock performer intake, HEI conversion with a re-curve kit, duals

       

[351wpower]

Edit:            4000 lbs. +/-

(not sure how to edit previous post)

[Cliff Ruggles]

Way too lean for what you are trying to do with it. 

Several ways to correct that issue, and those are really nice carbs for what you are doing once correctly dialed in.....Cliff

[351wpower]

Way to lean.   Yes.  Yes it is. Thank You for your time.

Thank You,