J Series engine swap possibilities

5JeepsAz

Bigger Hammer
May 10, 2021
151
Arizona
First Name
Paul
Willys Model
  1. Pickup
Willys Year:
  1. 1964
What am I into here? Might have a cracked block on my Tornado OHC 230. If that is the case, do I find another Tornado or swap engines? I have a No Tech build so am wondering about fitment for a rebuilt I6 with a 5speed. Thoughts?
 

stardog

Bigger Hammer
Nov 7, 2020
34
Las Vegas
First Name
Brandon Martin
Willys Model
  1. CJ
Willys Year:
  1. 1964
You could do the 242ci i6 4.0L w/ the AX15 5 speed transmission and the 231 transfer case. Early 4.0 are carb fed. I have been planning a 304 V8 AX15 231 swap for my 1986 Comanche.
 

Greaser007

Precision Fit
Mar 1, 2019
563
Anderson, California
First Name
Leonard
Willys Model
  1. CJ
Willys Year:
  1. 1946
You could do the 242ci i6 4.0L w/ the AX15 5 speed transmission and the 231 transfer case. Early 4.0 are carb fed. I have been planning a 304 V8 AX15 231 swap for my 1986 Comanche.
Brandon,
Good call on the 304. you will like it because it has good chug. twice the cubes of a L134 Willys 4-banger.


Here is why i like the 304 engine:
I have been running a 304 2bbl carb in my '77 Renegade since i purchased it in December of 1981 with 60k expressway miles.
The Renegade is a CJ-7 and it got a T-18 granny trans implant by me assisted with a Novak kit in '83, then carried me in and back out of the Rubicon trail for 16 summers. I got lucky and never broke. 2001 was my last Rubicon trek.
Anyway - in my now 39-years of ownership i have never removed a valve cover off of that engine. In my opinion, i would give AMC high regards for their engine. I fought overfueling while crawling on the Rubicon until I learned to drop the float level 1/8 to 3/16-inch (eye-ball) when hitting the trail head. The switch is quick because the top of the motorcraft 2bbl carb comes right off for quick adjustment of the float tab. I have never changed carbs in all the years of ownership.

Now, if _ _ _ you don't raise the float level back up for driving home, you will encounter a slight stumble pulling away from a stop light.

A stock amc 401 looks like a 304 and would really perk-up the comanche with great torque.

Paul,
The swap you mention may be the easiest and probably most affordable because I see inline 4.0L six's often on Craigslist for very cheap and affordable $$$$. and, you may wind up with EFI. win win
 

WA7OPY

Well Oiled
Aug 1, 2019
1,034
Missoula, mt
First Name
Phil
Willys Model
  1. Jeepster
Willys Year:
  1. 1947
Go with a 250 gm or a 300 ford L6, will work with your firewall and t90, and the 4.27 gears ratio will be right...A v8 will require you to beat the firewall, change transmission and gear ratios in the axels. Also a L6 will give you better gas milage over a v8...Phil
 

5JeepsAz

Bigger Hammer
May 10, 2021
151
Arizona
First Name
Paul
Willys Model
  1. Pickup
Willys Year:
  1. 1964
Brandon,
Good call on the 304. you will like it because it has good chug. twice the cubes of a L134 Willys 4-banger.


Here is why i like the 304 engine:
I have been running a 304 2bbl carb in my '77 Renegade since i purchased it in December of 1981 with 60k expressway miles.
The Renegade is a CJ-7 and it got a T-18 granny trans implant by me assisted with a Novak kit in '83, then carried me in and back out of the Rubicon trail for 16 summers. I got lucky and never broke. 2001 was my last Rubicon trek.
Anyway - in my now 39-years of ownership i have never removed a valve cover off of that engine. In my opinion, i would give AMC high regards for their engine. I fought overfueling while crawling on the Rubicon until I learned to drop the float level 1/8 to 3/16-inch (eye-ball) when hitting the trail head. The switch is quick because the top of the motorcraft 2bbl carb comes right off for quick adjustment of the float tab. I have never changed carbs in all the years of ownership.

Now, if _ _ _ you don't raise the float level back up for driving home, you will encounter a slight stumble pulling away from a stop light.

A stock amc 401 looks like a 304 and would really perk-up the comanche with great torque.

Paul,
The swap you mention may be the easiest and probably most affordable because I see inline 4.0L six's often on Craigslist for very cheap and affordable $$$$. and, you may wind up with EFI. win win

Thank you. I'm looking to swap in same engine as a stand in so I can drive it. Will let you know how that is going. Then, when I have the original engine out , maybe let it sit long enough to give ideas about how to improve the performance before I swap it back in. Too many mods for me on the I6, for this truck, for right now.
 

1960willys350

Bigger Hammer
Apr 14, 2017
107
Oregon
First Name
Zack
Willys Model
  1. CJ
Willys Year:
  1. 1946
Go with a 250 gm or a 300 ford L6, will work with your firewall and t90, and the 4.27 gears ratio will be right...A v8 will require you to beat the firewall, change transmission and gear ratios in the axels. Also a L6 will give you better gas milage over a v8...Phil
Swapping a v8 into an early Gladiator doesn't require any firewall modifications. They came from the factory with v8s starting in 1966 with the AMC 327, then the Buick 350, then AMC 304, 360, and 401. Also, I don't believe the early fullsize jeeps ever had the T90 in them. I'm not sure what 3 speed it was, maybe the T85? If it's a 4spd then it would be a T98.

To the OP, nothing will directly bolt in place of the 230 OHC except another 230. Do some searching on IFSJA and Fullsize Jeep Network, lots of build threads over there covering every engine swap imaginable. I know some have done the 4.0L 5 speed swap from later jeeps with good results.
 

Blindmelon

Well Oiled
Aug 10, 2014
2,255
Agua Dulce, CA
First Name
Larry
Willys Model
  1. Pickup
Willys Year:
  1. 1950
My pickup was pre butchered with a Ramber engine when I bought it... The front crossmember had been lowered about 4 or 5 inches.
Over the years I got plenty tired of the D18 and T90 even with the Saturn overdrive I added... So, I found a good used JEEP 258/T5 trans and
Dana 300 for $1200.... That works for me.. Imagine, no adapters..
 

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Blindmelon

Well Oiled
Aug 10, 2014
2,255
Agua Dulce, CA
First Name
Larry
Willys Model
  1. Pickup
Willys Year:
  1. 1950
You could do the 242ci i6 4.0L w/ the AX15 5 speed transmission and the 231 transfer case. Early 4.0 are carb fed. I have been planning a 304 V8 AX15 231 swap for my 1986 Comanche.
I purchased a brand new Comanche in 1990... 4.0 fuel injected and AX15 trans.... At 56,000 miles I sold the Jeep... The trans was junk and the hydraulic slave cylinder failed twice.... But hey, that's probably only me...
 

rocket

Well Oiled
Sep 3, 2015
2,366
Sierra Mtns
First Name
Rodney
Willys Model
  1. Wagon
Willys Year:
  1. 1963
6.9 IDI Diesel V8 even fits under the hood with a ZF 5 speed.
When I was 15 and old guy, (in his 30's) with a 392 Hemi in a 56 Ford F100 told me "You can put any engine in any vehicle. As long as you have a big enough Shoe Horn." The coolest thing was the Push Button Shifter on the dash.
6-24-2017_016.JPG12-9-2016_001.JPG
 
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