2.3 to 4.0 swap

[Jeff Rodgers]

Wanting to swap a 88 4.0 engine that was matched with an automatic with a 4 speed  from an 88 with 2.3. Will flywheels need changed ? Will the manual bellhousing with clutch and pressure plate bolt up to the 4.0?  The 4.0 was from a 88 Cherokee and the vehicle that  it is being installed in is a 88 Comanche and was already previously a manual. 

[eaglescout526]

2.3? Do you mean the 2.5L?

 

If so, the swap isnt worth your time for minimum power gain. And nothing from either engine swaps to each other so youll need a donor vehicle that has a manual to swap in. 

[fiatslug87]

14 minutes ago, eaglescout526 said:

the swap isnt worth your time for minimum power gain.

Spoken like a multiple 2.5L owner.

[eaglescout526]

8 minutes ago, fiatslug87 said:

Spoken like a multiple 2.5L owner.

Haha! yup, guilty. 

[89 MJ]

You’ll need the trans from the 4.0 Jeep too. Bellhousing was different between the 2.5 and 4.0. Though if you aren’t happy with the power of the 2.5, I think you’ll be disappointed with the 4.0 after doing all of that work. 

[Eagle]

On 5/23/2026 at 9:20 PM, 89 MJ said:

Though if you aren’t happy with the power of the 2.5, I think you’ll be disappointed with the 4.0 after doing all of that work. 

 

WHAAAAAAAAT ?????

 

The difference is VERY noticeable.

[89 MJ]

1 minute ago, Eagle said:

 

WHAAAAAAAAT ?????

 

The difference is VERY noticeable.

Didn’t say that the difference wasn’t noticeable. I am saying that the effort of swapping the engine, trans, driveshafts, and engine wiring is a ton of work when there are other engines you can swap in for similar amounts of work.