I know I know- I need to talk through this again

[jdub]

The Cj I found was more haggard than I thought at closer look. The tranny skid was welded on... I found that a early wrangler wouldn't be a bad option. I need/want a 4.2 with a serpentine belt configuration-which I currently have for my a/c- some wranglers have it. I will keep looking.

jsudar, Bennie at Hesco said he'd build me something fun, so tempting!

 

[jpndave]

I'll throw in my opinion here as well. My recommendation would be to go to a 5.3L GM engine preferably with the 4L60E automatic, but you can keep a manual if you prefer.

The 5.3 is roughly 100lbs lighter than your six, makes double the power and is far more efficient. They regularly get over 20 MPG in CJ/YJ/TJ conversions with sane sized tires and driving habits. The difference in power, drivability and performance is night and day. Yes, cost up front is more than some of the other options but by the time you get done messing around with the 6 and all the other bolt-on parts, you will be at or more than the same price anyway and still don't have the power, performance, weight and economy of the newer engine. Then you get to spend it all over again to get what you really wanted in the first place. If you want to see what one is like first hand, I can get you in the driver’s seat of several that have had the conversion and put you in touch with even more that can share their experience.

Imagine having an engine that would actually hold the vehicle at speed in overdrive. One that would crawl all day long and not miss a beat, and then take 1/3 less fuel at the pump! Better still, get an aluminum block version and save another 100 lbs! A lot of the need for lower gearing is gone as the torque is more than enough to overcome any shortcomings there especially when paired with a torque converter in the automatic.

An interesting tidbit - The last TJ that left here after a 6.0/4L60E conversion had to have the headlights re-aimed as they were shooting up into the sky from the reduced weight of the new power train. It was the iron blocked version, the aluminum one would have been that much more.

Don't get me wrong, the 6 is a stout, reliable engine. I am currently driving my son's '90 Cherokee while I finish up the 6.2L L92/6L80E conversion in my JK. It is pushing 240,000 miles and still running - not so strong and squeaking pretty bad, but it is still alive. The 258/4.0 is simply very dated technology; even the Legendary Chevy 350 is dated technology. Until you have seen or better yet felt the smooth efficient power of these newer engines, you don't know what you are missing. They can be had reasonably priced as thy have been made from '99 on (earlier if you want to look at an overpriced LS1) and every full-sized GM Truck/Tahoe/Suburban/Yukon and even some of the midsized rigs had them.

Just my two bits,

Dave

BTW, I do work for Novak who is a sponsor here. I am one of the lead techs and over R&D. My recommendation holds even if you don't use any of our parts - though they are the best in the business! ;-) Feel free to give me (or any of the guys) a call if you have any questions. We can do anything from complete power trains to just the pieces you need and the advice is FREE! There is a HUGE amount of knowledge on the website, again free for all! www.novak-adapt.com

 

[Gravy]

jdub.

buy my 4.2. It has serpentine belts and ac.

do a rebuild on it. swap it in over a weekend.

Teach your wife to drive stick, I am.

 

[Green-Tonka-CJ5]

I hear the 4cyl jeep motors are pretty peppy!

 

[Hickey]

I love the Jeep six motors. If you stick with a six, buy a wrecked XJ with the auto trans. The dana 300 will bolt on and you will have an overdrive.

On the other hand, there is nothing like the sound of a V8.

 

[neagtea]

It was a happy day for me when I unloaded the 4.2 out of my scrambler at the scrap yard. I went the old jeepers route and did a 360/727. I would prefer the over drive 700r4/4l6o trans. but what I have works for what I intended the CJ8 for.

 

[Green-Tonka-CJ5]

Propane fueled 360 with the tranny neagtea recomends

 

[DaveB]

Now Jedisdead has the right answer to me... get ahold of I think its DaveB he has a 4.0 in his scrambler... and he can tell you all the ins and outs....pros and cons

Yes I have a 4.0/aw4/d300 in my scrambler and it works great. There are times when I would like the v8 power but for most of what we do the 4.0 works very well and I get 21 MPG with it. I am always the last one to run low on gas on our trips. You can use the same motor mounts as your current six cylinder and with the EFI setup you have the wiring is already taken care of. The 4.0 that I used came from a wrecked low mileage 99 TJ which gave me the centered fan that you want for a CJ. Grand cherokee 4.0 motors up to 98 and XJ motors up to 2001 will also work. The XJ motors have an offset fan and will require some mods to center the fan.

 

[jdub]

This is still going! I appreciate all of the opinions. I ran into a Cleggs machinist. He quoted a great price if I drop the block off to them to get rebuilt. I have had 8+ years of flawless performance. I'm starting to think I need to keep this good thing going. I've put another 10k on it since I started this thread with no issues.

Hesco still enters my mind occasionally though.

 

[UNSTUCK]

I'll throw in my opinion here as well. My recommendation would be to go to a 5.3L GM engine preferably with the 4L60E automatic, but you can keep a manual if you prefer.

The 5.3 is roughly 100lbs lighter than your six, makes double the power and is far more efficient. They regularly get over 20 MPG in CJ/YJ/TJ conversions with sane sized tires and driving habits. The difference in power, drivability and performance is night and day. Yes, cost up front is more than some of the other options but by the time you get done messing around with the 6 and all the other bolt-on parts, you will be at or more than the same price anyway and still don't have the power, performance, weight and economy of the newer engine. Then you get to spend it all over again to get what you really wanted in the first place. If you want to see what one is like first hand, I can get you in the driver’s seat of several that have had the conversion and put you in touch with even more that can share their experience.

Imagine having an engine that would actually hold the vehicle at speed in overdrive. One that would crawl all day long and not miss a beat, and then take 1/3 less fuel at the pump! Better still, get an aluminum block version and save another 100 lbs! A lot of the need for lower gearing is gone as the torque is more than enough to overcome any shortcomings there especially when paired with a torque converter in the automatic.

An interesting tidbit - The last TJ that left here after a 6.0/4L60E conversion had to have the headlights re-aimed as they were shooting up into the sky from the reduced weight of the new power train. It was the iron blocked version, the aluminum one would have been that much more.

Don't get me wrong, the 6 is a stout, reliable engine. I am currently driving my son's '90 Cherokee while I finish up the 6.2L L92/6L80E conversion in my JK. It is pushing 240,000 miles and still running - not so strong and squeaking pretty bad, but it is still alive. The 258/4.0 is simply very dated technology; even the Legendary Chevy 350 is dated technology. Until you have seen or better yet felt the smooth efficient power of these newer engines, you don't know what you are missing. They can be had reasonably priced as thy have been made from '99 on (earlier if you want to look at an overpriced LS1) and every full-sized GM Truck/Tahoe/Suburban/Yukon and even some of the midsized rigs had them.

Just my two bits,

Dave

BTW, I do work for Novak who is a sponsor here. I am one of the lead techs and over R&D. My recommendation holds even if you don't use any of our parts - though they are the best in the business! ;-) Feel free to give me (or any of the guys) a call if you have any questions. We can do anything from complete power trains to just the pieces you need and the advice is FREE! There is a HUGE amount of knowledge on the website, again free for all! www.novak-adapt.com

Read this over and over again until it sinks in and you agree and go for it!