Question about a modified intake manifold

[dan juhasz]

Harms is swamped with work and is not taking any new work and he doesn'thave any clone hemi carbs for sale either. I have a single four barrel 426 manifold that I modified for use with Holley sniper. I had the center plenum divider milled down a good half inch as suggested by Holley. I was thinking about putting on this intake on for the summer and running a single four barrel carburetor until the dual quads can be restored.
Will the modification to the plenum divider affect the correct operation of a carburetor for proper fuel distribution ? What size of carburetor is appropriate for a stock 426 hemi? Double pumper or vacuum secondary?
Thanks for the feedback
Dan

 

[Runcharger]

If it was me I'd put on at least an 850 double pumper. A lot less complicated getting that to run right than a stock dual AFB setup with their staggered jetting.

 

[68-500]

I don’t have personal experience with that but , I think it would be fine, possibly better with center milled as it is. Using both sides of the carb to fill each plenum.

 

[topside]

I don't think it'd be an issue. Carb depends on usage & combo. For a rumpity 4-speed car I 'd probably use a DP, but an AT car or taller gears a vac secondary is arguably better.
Either way, an 850 will feed it on the street. A 750 or 780 will have a nice vac signal at lower RPM.

 

[dan juhasz]

I don't think it'd be an issue. Carb depends on usage & combo. For a rumpity 4-speed car I 'd probably use a DP, but an AT car or taller gears a vac secondary is arguably better.
Either way, an 850 will feed it on the street. A 750 or 780 will have a nice vac signal at lower RPM.

This gtx is a show cruiser , 727 auto with a 2:94 sure grip. It sees a fair amount of turnpike and parkway drives at 75+ mph. Vacuum secondary would be your suggestion? 850 too large for my combo?

 

[Runcharger]

Oh: More of a New Yorker Brougham setup. Go a 750 vacuum.

 

[Cranky]

I don't have much experience with the 2nd gen Hemi engine but know they pull harder in the upper rpm range and the big carb would be the one to go with if you are doing that but since it's mostly a show cruiser then a smaller carb would be the way. I still like the DP carbs since they perform very well but if you are versed well with the TQ's, then they can be your savior. Best street carb I ever had was a 71 TQ and man, it made a believer out of me. They do take some 'learnin' but they are well worth it. The Hemi is still an engine so there's no witch craft with it imo. Just gotta remember what the heads do for them.

 

[Nevada dan]

Why starve it
It’s a big block
850

 

[33 IMP]

Considering gearing and stated use: 750 vacuum.
Four gear, 3.55 rear, rumpety-rump? 850 dp
A thermoquad won't fit that intake without an adapter. Never was a fan of adapter use on thermoquads.... or quadrajets....
For your use, the cut down divider means nothing.

 

[topside]

I agree with the smaller carb - 750 vac sec - for this application. All a DP will do in this combo is wash the walls with fuel.
Not a fan of carb adapters either; but I do like T-quads.

 

[forphorty]

I agree with the smaller carb - 750 vac sec - for this application. All a DP will do in this combo is wash the walls with fuel.
Not a fan of carb adapters either; but I do like T-quads.

A Dp will NOT wash the walls with fuel.

 

[topside]

Ohhhkaayyyy...