Want to remove the Weber and replace with a Quadrajet

[Jeremy Martin]

I tried to find this question with the site search but couldn't find it. I am thinking about ditching the Weber and going to a Quadrajet to get some better performance offroad. Will the Quadrajet bolt right on, or do I need an adapter for the AMC 258 i6 / 4.2l inline 6?
Or, am I jumping the gun replacing the Weber. It was damn near new when I purchased the jeep, but it can't handle even a mild incline. Can they be tuned for some better performance?

 

[johnnyreb]

yes you need an adapter. skip the Qjet, ditch the weber and install a motorcraft 2100/2150.

 

[Jeremy Martin]

yes you need an adapter. skip the Qjet, ditch the weber and install a motorcraft 2100/2150.

Okay, I'll take a look at the Motorcraft. Will I need an adapter for it as well?
Forgive me, to me carbs are some kind of black majic that only the chosen few fully understand.

 

[johnnyreb]

yes the adapter changes it from a small base two barrel to a large base two barrel. Mr gasket makes one, but it's cast and while mine hasn't warped, I am told they will. There is a member on here who sells on ebay and he sells an all machined aluminum adapter. You could also install a fuel injection if funds allow.

 

[Jeremy Martin]

yes the adapter changes it from a small base two barrel to a large base two barrel. Mr gasket makes one, but it's cast and while mine hasn't warped, I am told they will. There is a member on here who sells on ebay and he sells an all machined aluminum adapter. You could also install a fuel injection if funds allow.

funds for sure do not allow for fuel injection as much as I would like to.
I'll take a look at eBay for the adapter. I was hoping I could sell the Weber and recover most of the cost for the switch.

 

[elwood blues]

I tried to find this question with the site search but couldn't find it. I am thinking about ditching the Weber and going to a Quadrajet to get some better performance offroad. Will the Quadrajet bolt right on, or do I need an adapter for the AMC 258 i6 / 4.2l inline 6?
Or, am I jumping the gun replacing the Weber. It was damn near new when I purchased the jeep, but it can't handle even a mild incline. Can they be tuned for some better performance?

I have heard very good things about a properly tuned Weber carb. I wouldn't jump the gun on ditching it. Get one of the Weber carb books, and see if you can dial it in. It will be A LOT cheaper than replacing the carb, even with an eBay MC2100.

You can buy this online, heck your local big box parts store may carry them in with all of the other Haynes/Chilton's manuals.

 

[Jeremy Martin]

I have heard very good things about a properly tuned Weber carb. I wouldn't jump the gun on ditching it. Get one of the Weber carb books, and see if you can dial it in. It will be A LOT cheaper than replacing the carb, even with an eBay MC2100.

You can buy this online, heck your local big box parts store may carry them in with all of the other Haynes/Chilton's manuals.

This looks like the cheapest way to start. Thank you.
I was fooling around with it today and found a vac leak at the base. Going to see if I can find a new gasket tomorrow. Or maybe some silicone.

 

[CJim7]

The Quadrajet is an awful lot of carb for a AMC 258 i6 / 4.2l , I don't think you would be happy with performance...particularly when the secondaries open up. As was suggested, the Weber can be a great carb. It mostly begins with re-jetting...as these things come over-jetted from the factory.

 

[RubberDuck]

I've messed with Webers and have found them to be finicky. I recently put one of Gronk's MC2150 kits on my 79 AMC 258 i6 / 4.2l and it's made a world of difference. He sells fully rebuilt 2150s on eBay complete with a machined adapter, gaskets, proper air cleaner, throttle linkage etc. It was pretty straight forward to install and tune. He will also jet your carb to your needs if you tell him to. I think my kit was less than $400 including a new electric choke, air cleaner, etc. I'd say I picked up at least 10% in the HP dept, maybe more.

 

[jdarg]

The Quadrajet is an awful lot of carb for a AMC 258 i6 / 4.2l

Rochester makes 2 barrel versions of the quadrajet. I think they are good carbs. The overall fuel metering is superior to a 2100 IMHO.

 

[Petescj]

Rochester makes 2 barrel versions of the quadrajet. I think they are good carbs. The overall fuel metering is superior to a 2100 IMHO.

Care to share some info if you have the time? I havent heard much on this option.

 

[johnnyreb]

being as quadrajet means 4 jets. Would that make a rochester 2 barrel just a two barrel or a dual jet?

 

[Mark W]

The old rochester two barrels were 2 jet (one per barrel) they did not have primaries and secondaries. if you can tune the webber I think you would find that the closer you get to a good tune the better it will work overall.