Squarebore to spreadbore

[Matt_J10]

I've currently got a quadrajet on my J10/360, with a stock 4bbl spreadbore manifold, that presumably originally had a MC4350. The previous owner put the q-jet on it with an adapter of some sort. I've been having issues with the q-jet recently and admittedly I'm no good at tuning these carbs. I'm considering throwing some sort of aftermarket square bore carb on it, potentially a 1406 (I know these get mixed reviews but I've had good luck with one in the past and can get one relatively cheap).

My question is, can I get away with an adapter such as this: https://m.summitracing.com/parts/edl-2696
?

I know I can swap the manifold but I really don't feel like it.

[derf]

You want one that has the 4350 pattern.

https://www.summitracing.com/parts/trd-2199/overview/

[Tatsadasayago]

The factory manifold is actually a good one as the smaller runners help with lower end torque. The adapter derf pointed out is exactly the correct one. Many people try to use a spreadbore adapter and they often end up with vacuum leaks.

[Matt_J10]

Thanks!

[REDONE]

Above is totally correct! Don't feel bad about the Q jet either. It's a "love it or hate it" carb and there are PLENTY like myself in the "hate it" camp. If I had a perfect, brand new Rochester Qjet, I would trade it for a rock that makes a better for stopper.

[Tatsadasayago]

FYI: If you go with a 1406, do yourself a favor and add the offroad kit. If you do any serious wheeling at angles, big bumps etc. this will minimize flooding and fuel starvation. I love my AFBs but they can be a real pain offroad.

[Matt_J10]

Yea when I got the Jeep and realized it had a Q-jet I was optimistic and figured those that complained just didn't know what they were doing, now I find myself in the other camp...

I will definitely go with the off road kit.

[FSJunkie]

Quadrajets ran great when they were new. Most factory carburetors did.

The problem is people screw them up and lose parts over the years.

[Cecil14]

The biggest problem with Q-Jets isn't tuning, it's the soft bodies. The throttle shaft wears out the holes in the body and you end up with vacuum leak you can't fix. There are some people that have bushed the bodies with bronze bushings, but in the end it's way more work than it's worth.

*IF* you can find a good quality Q-Jet core, they run amazing, but good luck with that.


aa

[Charles Kline]

You want one that has the 4350 pattern.

https://www.summitracing.com/parts/trd-2199/overview/

Its nuts that that thing costs $65.

[kansasboy001]

The biggest problem with Q-Jets isn't tuning, it's the soft bodies. The throttle shaft wears out the holes in the body and you end up with vacuum leak you can't fix. There are some people that have bushed the bodies with bronze bushings, but in the end it's way more work than it's worth.

*IF* you can find a good quality Q-Jet core, they run amazing, but good luck with that.


aa

It really isnt that hard to do a bushing job. Only really bad thing with quadrajets is a warped air horn, however, that can be somewhat fixed with multiple or extra thick gaskets.