to weber or not to weber that is the question?

[1986cj7]

I am building my AMC 258 i6 / 4.2l .030 over 260 grind comp cam 96 4.0l head maybe Chevy valves not sure. I've read a lot about the Weber's lately, and know about tune the weber and or re-jet them. Plus cable linkage issues. But my question is also should I go all in and get an Offenhauser intake and get a 390 Holley or a Holley 475 truck avenger. I think the truck avenger would be too much carb but like the supposed angles to be able to run at. Or just go cheap keep my old intake and get a weber or Motorcraft 2100, 2150? Any thoughts opinions and experience welcome.

 

[Torxhead]

If you run at steep angles, a fuel injection kit will eliminate any issues there. Plus more performance than a carb will give.

 

[PaRenegade]

If you go weber, go straight for the 38 and not the 32/36, since you have that engine work.

 

[ThisGuyUKnow]

If you run at steep angles, a fuel injection kit will eliminate any issues there. Plus more performance than a carb will give.

x2 on this. You'd really be taking advantage of the 4.0 head.

 

[oss]

I run a Weber. The only problem I've had was that my old tank had some rust issues. Once I replaced it everything has been smooth.

 

[ThisGuyUKnow]

I run a Weber. The only problem I've had was that my old tank had some rust issues. Once I replaced it everything has been smooth.

a poly tank is a good upgrade

 

[rlitavecz]

My engine is similar to yours and I used a 38 Weber on a 2 bbl manifold for a year. I rejetted the Weber and it worked reasonably well. The only issues I had was low RPM (<2000) hesitation.

This spring I replaced the carb with TBI. The engine will pull smoothly from 800 rpm even in 2nd gear hi range off road. I am still running the mid 80s 2bbl manifold.

 

[Old Dog]

for steep angles forget the carb, go EFI.

 

[deadfeat]

Doing a 4.0l MPI swap from a 93 XJ was the way to go for me. FI All the way.

Sent from my Galaxy S3 with Taptalk 2

 

[1986cj7]

My engine is similar to yours and I used a 38 Weber on a 2 bbl manifold for a year. I rejetted the Weber and it worked reasonably well. The only issues I had was low RPM (<2000) hesitation.

This spring I replaced the carb with TBI. The engine will pull smoothly from 800 rpm even in 2nd gear hi range off road. I am still running the mid 80s 2bbl manifold.

How much did the TBI cost you and what if any mod to the intake did you have to do? My budget is $3000 for the whole motor rebuild. No I don't want to go with a 360. Haven't talk to my machine shop yet so not sure how much head work going to Chevy 1.94 intake and 1.50 exhaust valves, porting, and block work will cost.

 

[rlitavecz]

I bought the Howell TBI kit that uses GM parts from 88-92. Easy to install for the most part and worked perfect from the first time I started it. The kit was $1195. check it out here:
http://howellefi.com/jeep-tbi-products.html

The Weber is around $300 and is a kit that uses your stock 2bbl manifold. The Howell kit also uses your 2bbl manifold and requires no modifications. Both kits have adapters to bolt the carb or throttle body to the manifold. The difference in performance is amazing. I switched from the Weber 38 to the Howell kit. There is definitely more power from the TBI. There is no stumbling at low RPMs and no waiting to warmup the engine or choke to adjust. Turn the key and go.

Keep in mind that you will need to replace your head bolts with bolts for a 4.0 engine. Half of the bolts are a different length. I got mine here: http://headbolts.com/Jeep-AMC 232 i6 -244-AMC 258 i6 / 4.2l -4.0-engine-head-bolts.html
I bought the chbs-1128 set at $45.


You will also need to install an exhaust manifold for a 4.0 engine. I got a used manifold from a 95 Cherokee that was cracked. I welded it up and cleaned it with a wire wheel on a grinder, Its SS and polished up nicely. This is a tube header from the factory. You will need to have an exhaust pipe made to fit the header and clear your clutch linkage. You can weld up your own or have a good exhaust shop build it. I made my own from 2" pipe, but had a shop duplicate it in 2-1/2" after installing the TBI. This really helped! I installed a Dynomax 2-1/2" VT muffler and had the tailpipe duplicated in 2-1/2". Sounds nice!

BTW my cam is Comp Cam 235 grind. Lots of bottom end torque. My engine never exceeds 4500 RPM, even when climbing sand hills with the throttle wide open.

Money is always an issue, but I know that I spent good money after bad. I wish that I had installed the TBI when I built the new engine.

Good luck!

 

[1986cj7]

Thanks rlitavecz for the links. Will have to see how much my rebuild cost and see if the TBI is in the budget. So what is every ones thoughts on the weber 38 and or Holley Truck Avenger?

 

[PaRenegade]

So the Howell costs more than just the initial kit itself. Curious, why do you need the different bolts and exhaust manifold when your replacing something related to neither? Excuse my ignorance but I know nothing about the Howell system.

 

[ThisGuyUKnow]

Thanks rlitavecz for the links. Will have to see how much my rebuild cost and see if the TBI is in the budget. So what is every ones thoughts on the weber 38 and or Holley Truck Avenger?

You can save a lot of money doing a junkyard fuel injection swap. Since you already have a 4.0 head I'd recommend finding a 91-95 yj or Cherokee in the local pick and pull and pulling the engine harness.

 

[rlitavecz]

So the Howell costs more than just the initial kit itself. Curious, why do you need the different bolts and exhaust manifold when your replacing something related to neither? Excuse my ignorance but I know nothing about the Howell system.

The bolts and exhaust are needed to convert to the 4.0 head. The Howell system IS complete.

 

[rlitavecz]

You can save a lot of money doing a junkyard fuel injection swap. Since you already have a 4.0 head I'd recommend finding a 91-95 yj or Cherokee in the local pick and pull and pulling the engine harness.

You could also look for a 1988-92 GM pickup to scavenge the TBI system from. That is the basis for the Howell system, they make it easy by building their own harness, supplying new sensors, adding a 2bbl conversion adapter, and rebuilding the throttle body. They also test the computer and offer a warranty.

 

[PaRenegade]

The bolts and exhaust are needed to convert to the 4.0 head. The Howell system IS complete.

So your saying if your not changing to a wrangler 4.0 head you can disregard the earlier post about needing the different bolts and ex. manifold?