4.2 to 4.0 swap?

[seanmnew]

What would it intail to swap the AMC 258 i6 / 4.2l for the 4.0? I have done swaps before, but not this one... would the tranny bolt up? or would i have to use the 4.0 tranny? if i used that could i use my Dana 300 ? or would it be better and easier to do the 4.0 head swap? I am just trying to get rid of my carbureted stuff

 

[LongHorn]

What would it intail to swap the AMC 258 i6 / 4.2l for the 4.0? I have done swaps before, but not this one... would the tranny bolt up? or would i have to use the 4.0 tranny? if i used that could i use my Dana 300 ? or would it be better and easier to do the 4.0 head swap? I am just trying to get rid of my carbureted stuff

The motor mounts are different, I'm all most positive the bell housing is different. There are adapters available. The head swap is an option, Intake & exhaust are different. What problems are you having with your carb?

 

[seanmnew]

What problems are you having with your carb?

I currently live in Colorado Springs, which sits about 6300 or so feet, and i do most of my wheeling at 8000 to 14000 feet! The carb is just not reliable enough for me, i have stalled out on steep hills when it floods out, and im just tired of going down hills backwards! To me a throttle body or fuel injection is priceless!

 

[LongHorn]

I currently live in Colorado Springs, which sits about 6300 or so feet, and i do most of my wheeling at 8000 to 14000 feet! The carb is just not reliable enough for me, i have stalled out on steep hills when it floods out, and im just tired of going down hills backwards! To me a throttle body or fuel injection is priceless!

It's cheaper to convert to propane. All you need is a mixer & a tank, I have some buddies that use fork lift tanks. Tuneups last longer, it runs cleaner & it'll run upside down. Better have dry sump with a big oil tank for that though. I'm running a "Holley Off Road Avenger". It's far & away the most reliable & trouble free carb I've ever run. I've run a lot of carbs, this is the best. I understand the changing altitude issue though.

 

[LongHorn]

It's cheaper to convert to propane. All you need is a mixer & a tank, I have some buddies that use fork lift tanks. Tuneups last longer, it runs cleaner & it'll run upside down. Better have dry sump with a big oil tank for that though. I'm running a "Holley Off Road Avenger". It's far & away the most reliable & trouble free carb I've ever run. I've run a lot of carbs, this is the best. I understand the changing altitude issue though.

Oh it'a also 105 octane so you can mill your head to increase compression. & it's cheaper than gas to boot.

 

[seanmnew]

I dont believe i feel like going propane lol, it took me long enough to get to learn all the workings of a gas engine, dont feel like dealing with more!

 

[LongHorn]

I dont believe i feel like going propane lol, it took me long enough to get to learn all the workings of a gas engine, dont feel like dealing with more!

The mixer is less complicated & has fewer parts than a carb. It' pre- vaporized & wants to stay that way unlike gasoline that want to be a liquid. They make simple conversion kits, you can even keep the stock carb in-place so it's dual fuel gasoline or propane.

 

[LongHorn]

Here are a few pic's

 

[LongHorn]

For the money it's hard to beat. You'd think I was on commission, but I just think it's cool. :drool:

JEEP AMC 258 i6 / 4.2l PROPANE KIT FOR 6 CYL. CARBURATED ENGINE

Price: $695.00
This item is in stock
Quantity:
Brief Description
Detailed Description
Specifications

FREE SHIPPING TO THE 48 STATES
INCLUDES: IMPCO ORIGINAL MIXER
ALSO: IMPCO STYLE MODEL E CONVERTER:

ADAPTER TO FIT YOUR INTAKE MANIFOLD 3 1/4" x 1 7/8" bolt pattern (not pictured) :​

EDLEBROCK AIR FILTER ALONG WITH ALL HOSING, FITTINGS ETC. TO COMPLETE THE INSTALLATION
NOTE: GENERAL INSTRUCTIONS INCLUDED

SHIPS IN 1 OR 2 DAYS FROM ORDER
FREE SHIPPING IN THE 48 STATES​

 

[seanmnew]

one thing i have not noticed is it saying anything about the ability to run as a daily driver, could i set this up to run gas normally and propane when i go wheeling? or would it be cost effective enough and not too much on the engine to run propane for daily driving?

 

[LongHorn]

one thing i have not noticed is it saying anything about the ability to run as a daily driver, could i set this up to run gas normally and propane when i go wheeling? or would it be cost effective enough and not too much on the engine to run propane for daily driving?

I guess it would depend on availability of propane in you area. It's no problem here. My wheeling buddy runs it every day in his rig. They make a dual fuel kit so you can run gasoline or propane.

DUAL FUEL PROPANE & GAS KIT V8 ENGINES & HOLLEY 4 BRL.

Price: $950.00
This item is in stock
Quantity:
Brief Description
Detailed Description
Specifications

FREE SHIPPING TO THE 48 STATES sku

Click Here. Double your traffic. Get Vendio Gallery - Now FREE!




APPLICATION: ANY ENGINE USING A HOLLEY 4 BARREL W/5 1/8" AIR HORN
FEATURES: ALLOWS YOU TO RUN PROPANE OR GASOLINE
NOTE: PROPANE MIXER MOUNTS ON TOP OF GASOLINE CARB.
INCLUDES: EDELBROCK 14" AIR CLEANER, IMPCO STYLE MODEL E VAPORIZER, IMPCO CT425M-2 MIXER, ALL MATERIAL TO COMPLETE UNDER THE HOOD INSTALATION

FREE SHIPPING TO THE 48 STATES
SHIPS IN 1 OR 2 DAYS FROM TIME OF ORDER (IN MOST CASES)​

 

[BrockGrimes]

$300 bucks and put together a throttle body setup.

You can take a throttle body off a 4.3L chevy and with an adapter plate, computer and misc sensors can make your AMC 258 i6 / 4.2l throttle body injected. It's simple easy to work on and it's pretty cheap.
BustedJeep.Com - In The Garage

 

[2lostspace]

On the propane set up, how does it work in the cold weather? I have dealt with it on forklifts and when it got down around freezing the thing would freeze up and not work. Have you had any issues like this?

 

[seanmnew]

that is a good point about the cold weather, there is a LOT of days here in Colorado when its below 0 degrees

 

[Old Dog]

$300 bucks and put together a throttle body setup.

You can take a throttle body off a 4.3L chevy and with an adapter plate, computer and misc sensors can make your AMC 258 i6 / 4.2l throttle body injected. It's simple easy to work on and it's pretty cheap.
BustedJeep.Com - In The Garage

The TBI works great on steep hills and off camber.

 

[Kman]

I swapped in a 4.0 from a $200. rolled over XJ. Installed a 4.0 flywhheel grafted in a YJ harness and the XJ computer. I used the Hesco pilot bushing and modified my T-176 bellhousing and made an adapter to mount the CPS. Got the '91 style VSS and mounted an external fuel pump(used a NAPA replacement YJ pump). Google Jeep CJ4 .0 swap all the info is out there. I spent more time researching it than doing the swap. I am VERY pleased with the performance of the 4.0 and highly recommend the swap.

 

[mtruckstuff]

My two cents:

The sweetest of swaps. Go with a 4.0 in front of an NV3550, use a clocking ring and keep the Dana 300 . Pretty much bolt up.

You gain a 4.02 first and .73 Overdrive . Throw in a 4:1 LoMax to get a 73 crawl. Beef the axles, add 35's, a 4" lift and you have quite a rig you can still drive on the street.

I forgot, you also get an injection system engineered from the factory for the 4.0. Easy to fix and diagnose.

Or do an NV4500 and get a 102 crawl.

Paul

 

[Kman]

I just went into detail about how I swapped the 4.0 into my CJ5 on this thread http://www.jeep-cj.com/forums/f2/using-yj-4-0-intake-manifold-cj-4-2-a-2503/ probably no sense in reposting it here.