I would think the best swap would be the 4.0 straight six, but I don't know if it uses the same tranny. You might want to try asking on the SWB board, if you haven't already.

I doubt the vortec v6 will bolt up directly, but I could be wrong.

 

Lee,
I have two different friends who have the same delimma. The best thing to do is to buy a Jeep with a 4.0 and be done with it. The 2.5 is fine if you can handle the 4cyl power. The AX-15 is not very strong although it is the better of the tranny's that came with the Jeep. To put in a new motor, you will need all new wiring, heavier springs, stronger tranny, emissions crap, etc.
If they have already put parts into their 2.5 Wranglers, they should be ready to switch them out when they purchase a newer Jeep.

 

The Vortec will NOT be a direct bolt in, nor will the 4.0. The 2.5 bellhousing pattern is the same as the GM 60 degree V6 though such as the crappy 2.8 V6. The 2.5 used the AX-5 not the AX-15. The AX-15 was used with the 4.0. You can't even used the stock transfer case with an AX-15 it has a different input spline 21 for the 4 cyl. VS 23 for the 6 cyl. You might check out the 3.8 front wheel drive V6 I think it is 60 degree not 90 degree. I looked at every option when I had the YJ and TJ with the 2.5. Now that said Advance Adapters makes a bellhousing for the AX-5 transmissions to Chevy V8 and 4.3 for the Jeep, part number 712565. Ironically they also make one for the AX-5 Toyota under a different part number, 712560, for the Buick V6. They both are for the AX-5 so I don't know what the difference is or why they don't list both bellhousings for the Jeep and Toyota. They look the same to me on the tranny side. Other than that I think you would have to change the whole drive train or have another adapter for the tranny ot t/case to keep any original parts.

 

Carey's right about the bellhousings. A bud of mine & RQs is in the middle of an engine swap/upgrade in his XJ... the 2.8L V6 was the biggest POS GM ever did & his has like 300K on it... So he dropped in a MPI(?) 3.4L V6 out of a late Camaro. Just has to figure out the deal with the "tamper proof ignition" (some junk that'll only let it start *if* the key chip jives) and it should be ready to rock.

 

Thanks for the replies. I searched the SWB, but I know you guys, so I trust what you say.

I will pass the info on.

 

Dave, what you need to do for the ignition is measure the resistor on the key..you do have the key?

Anyhow, just wire in a resistor of the same value on the appropriate leads to the ECM or BCM, whichever that particular car had to validate the resistor.

Pete

 

Key?

Not sure if he has "the" key, but he's got "a" key

He's on it (has the schematic)... is just waiting for time to sit down and put the resistor inline so he can fire it.

His woody has been out of commition since late '01-early '02, so he's definitely ready to get it back on the road!