chevy 350 conversion

[jeepincoco]

I have a 93 yj thinking on putting 350 chevy in it currently has a 2.5 4 banger. I would like some info on how hard it is to do the swap over and how expensive. ANY INFO WOULD BE HELPFUL.

[OhioYJ]

Obvisuly you can buy many of the parts to do this as its fairly common. However, its not just as easy as dropping in a small block, and welding on new motor mounts. Your AX5 transmission has no hope of living, and your NP231 transfer case won't just bolt up to another transmission. Next you axles aren't going to live very long under the power that 350 will put out. Overall this is a very involved project, if this is your daily driver, forget about it, because you won't be driving it for a while after you start the swap.

There have been many posts on this in the past, do a search and it will bring many options up.

[brkitnowfixit]

what he said im just now finishing this project after 6 months

[HotRod YJ]

Did mine plus the full SOA in 2 weeks, afternoons and weekends after I got home from work. BUT I had a really good idea what I was doing and parts already arrived and ready. That included making my own driveshafts, custom radiator mounts, etc. moving the fuel pump to an external electric, and all the jazz that comes with a swap such as this. I used a universal weld in motor mount crossmember. Cut to the correct width and weld it in between the frame rails. Built my own Anti-wrap bar a bit later but that could easily be done in one more afternoon. All depends on your experience level and what you can and cannot do. As far as axles go, yes they definetly need to be upgraded if you ever intend to beat unmercifly on it off road. I drove mine on stock axles and 35's for over 2 years before I did the axle swap. Never had any axle issues, because I understood what breaks axles and how to protect them.

Use the search feature. This topic has been discussed MANY times.

[Slowride]

Do I see a GMPP ZZ383 in your future? 425 horse and 460ft/lbs of torque. That torque curve is as flat as Nebraska too. A nice engine.

[jeepincoco]

hey guys how about trans i have a th350 ready to go but everyone seems to lean more on 700r4. I know about o/d gear is it really a better choice yo go with 700r or 350tubo?This jeep is my first and i plan on doing a little camping and towing a small pop up camper no radical horsepower.Just more than i have now. Maybe a little mudding but mostly towing.

[HotRod YJ]

700R4 has a deeper first gear ratio, plus the overdrive so you get better overall gearing at both ends of the spectrum. Better first gear for offroad and low end power, then OD for cruising down the highway. The TH350 is actually a bit stronger, but with a good trans cooler, you wont have any issues with the 700R4 as long as you get a 1989 or newer version of it. When the 700R4 first came out in the early 80's it did have alot of issues. They say earlier than 1988 leave them alone but the newer ones are just fine. One mistake ALOT of people make with the 700R4 though is adjustment on the TV cable. Most peple think it's just the kickdown cable for passing gear like on the TH350 but it's not. If this cable is not adjusted properly, or I've even seen them not hooked up at all, you'll destroy the trans just driving it around the block. As long as you take the time to properly set the cable adjustment (which is very easily done), you wont have any issues.

Still nothing wrong with the TH350, just the 700R4 does have some gearing advantages and that OD will help a bit with todays gas prices.

[cesario]

I have a 1990 GM Suburban with a V8350 and an auto tranny.

totalled it 6 years ago and wanna take out the motor.

what chances I have to install it on the TJ regarding the motor`s condition. its all rusted and doesnt look so nice.

[brkitnowfixit]

put a breaker bar on the crank pulley bolt and see if she turns
if she turns ata minimum i would take off the heads and see what the cylinders look like.

if they have a little lip on them id have that removed the heads checked and reinstall everything of course you have it that far apart you may as well rebuild it.

[HotRod YJ]

All depends on the conditions in which is was stored. Was it rained on or was it under a hood, etc. Check and see if it turns easily with bar on the crank. If it does, I'd run it. I wouldn't pull a head unless I thought it had more serious rust in the cylinders. I disaggree with reaming out a lip in the top of the cylinders if it has one. If you do that, you need to build the motor anyway. As long as the cylinders aren'ty rusted up (wont turn fairly easily) run it. It may be worth replacing gaskets or it may leak. That would also give you a chance to pull the oil pan off and look at the bottom end. If the bottom end looks clean and not rusted, odds are the cylinders are okay as well. If the bottom looks nasty, then the whole thing needs to come apart.

[disturbed 1]

Don't forget about your state's emissions laws if you plan on registering it and driving it on the street. The laws might put a stop to the swap before it even starts.

If it's going to be a trail only ride that isn't registered, anything goes.

[cesario]

Originally posted by HotRod YJ:
All depends on the conditions in which is was stored. Was it rained on or was it under a hood, etc. Check and see if it turns easily with bar on the crank. If it does, I'd run it. I wouldn't pull a head unless I thought it had more serious rust in the cylinders. I disaggree with reaming out a lip in the top of the cylinders if it has one. If you do that, you need to build the motor anyway. As long as the cylinders aren'ty rusted up (wont turn fairly easily) run it. It may be worth replacing gaskets or it may leak. That would also give you a chance to pull the oil pan off and look at the bottom end. If the bottom end looks clean and not rusted, odds are the cylinders are okay as well. If the bottom looks nasty, then the whole thing needs to come apart. we took out the motor this morning out of that totalled 1990 suburban.

we started it and......... ITS GOOD... we`re so exited. also was found that the auto tranny its a TH400, one of GM heavy duties.

Cheers and will keep u updated. we`re making the swap these days. smile.gif