Chevy 350 swap??

[cdj1676]

im thinking about putting in a 350 in my CJ5....could i keep the stock tranny or would i have to replace everything in the drivetrain......

[Blupupher]

there are adapters that allow you to keep the stock transmission for most applications. Go to the 4WDH site and search adapters and it will bring up what they have.

[LWB]

im thinking about putting in a 350 in my CJ5....could i keep the stock tranny or would i have to replace everything in the drivetrain...... Depends on what tranny your '5 has. A 350 will chew up & spit out just about any stock Jeep trans you might have, except a T18 or maybe a T176.

[cdj1676]

well in that case, what tranny should i use??

[LWB]

OK, Here is where I need info from you- First off, I am assuming your '5 is '72 or later- If it isn't then I don't think you're quite ready to go through with this. It can be done, but a LOT of work!!! You have to let me know if you prefer manual or auto trannies (manual much easier-shorter drivetrain) Also if you're building this for off road or if it is going to be street driven only. Sorry to pepper you with all this, but if I go through all the ways I've seen Chevy small blocks swapped, this thread wouldn't have enough pages.

[thejeepingoat]

yes, drive lines can be a horror with a CJ5, if you are coverting over to an automatic transmission along with the 350, plus lifting the vehcile, it is a nightmare. Cj5s are not the longest of vehicles. a manual transmission would be in your best interest.
-goat

[5.0L 44GPW]

If you are going to use a Chevy engine your best bet for a tranny is a SM420 it can be found in alot of early chevy pickups. It is just over 10 inches long and has the lowest 1 gear of all the 4 spds out there Advanced adapters makes an adapter to fit the 420 to a spicer 20 transfer case or the 300 depending on year of your CJ. You can use a t-18 or t-19 but then you will have to use a adapter in the front and the rear of the trans that could get pricey.

[LWB]

If you are going to use a Chevy engine your best bet for a tranny is a SM420 it can be found in alot of early chevy pickups. It is just over 10 inches long and has the lowest 1 gear of all the 4 spds out there Advanced adapters makes an adapter to fit the 420 to a spicer 20 transfer case or the 300 depending on year of your CJ. You can use a t-18 or t-19 but then you will have to use a adapter in the front and the rear of the trans that could get pricey.I've got a SM420 in my '6, and it's not for everyone. While I like the low 1st gear, in NC the rocks that get crawled are a lot slimier than you're used to. Quick application of wheel speed is sometimes the only way up some of the trails in Tellico. Not the ideal place for ultra-low granny gearing & hard shifting. On a street only rig, it would be even worse. It's like having a three speed W/an extra low range. Or to put it another way, like driving a dump truck. (basically what these trannies are from) Also there is no adapter needed for a T18 W/a D20 as they were available from the factory this way.

[5.0L 44GPW]

LWB--- that was just an option he could use, Im not real sure why the Chevy Engine is a popular engine for the jeep swap yes they are easy to get and cheap to build but not after you get done with your adapters. I own a wrecking yard here in Idaho and had my pick of about any engine
under the sun for my GPW by far the easiest to put in was the Ford 5.0 because of the reason you stated the spicer 18 or 20 transfercase came behind it. I just used a scout output shaft in the Ford T-18 redrilled the tranny case for the scout adapter and bingo no high priced adaters. I had a 1998 S-15 Vortec 4.3 would have loved to use it but it would have sent me to the poor house in adapters to save space I wasnt about to use a SM465 and 205 or 208 that was not an option with the space I had to work with, Im kinda a Ford guy anyway. Now once again these are options AND everyone has prefrences. Heck I go wheelin on the Rubicon with a guy that has a Dodge 440 in a 57 CJ5 WITH a T-90 behind it and never had 1 ounce of problems with it!!!!! :* :* :* :* :*

[thejeepingoat]

hey GPW, can u get ur fellow jeeper a deal on a runnin 4.3? mines kaput

[LWB]

Heck I go wheelin on the Rubicon with a guy that has a Dodge 440 in a 57 CJ5 WITH a T-90 behind it and never had 1 ounce of problems with it!!!!! :* :* :* :* :* Yikes!!!! Yeah, sometimes you never know what will hold together!! :shock: :shock: :shock: I've always thought the Windsor was way underrated as a Jeep engine. Its compact size and light weight make it a natural choice. I've always been a Mopar man, thats why I swapped the Dodge 360 in my Scrambler. But for an original D300/999auto CJ, it is about the cheapest CJ swap you can do. No adapters whatsoever, and motor mounts are all factory Dodge or Jeep. The 3.58" stroke makes excellent low end torque. I've thought about the 440, but it sure is a heavy beast to put in a CJ!!

[cdj1676]

Actually, my CJ is a 68' with the 3 speed tranny. i really dont know much about these motor swaps yet but i am learning. The reason i chose the 350 was because you can get them cheap and build them up real easy. I dont plan on doing any rock crawling any time soon, just some moderate off roading and beach cruising. i just want an easy combination that people make conversions and adapters for so i dont have to fabricate everything.......thanks for the info......keep it coming

[LWB]

I believe your tranny is a T90. If you're not going to be too rough on it, you can keep it alive. (see GPW's post above) There is an adapter (Trans Dapt?) that will adapt the T90 to your small block Chevy. The front of early CJs is 3" shorter than the '72 and up. The grille will have to be either trimmed or replaced w/a '72 & up style to fit the engine & rad at the same time. (This will give more room, but not as much as a '72 & up.) I would also recommend getting Jeep 4x4 Performance Handbook by Jim Allen, and Jeep Owners Bible by Moses Ludel

BTW- I'll ask a couple friends w/350s about info on the adapter (it's supposed to be real cheap) & post it unless some one else beats me to it.

[cdj1676]

thanks for the info, and i will check that book out. if the 350 in the 68' CJ is more of a problem, would you recommend another V8??? just curious

[LWB]

Actually, if you want to keep the T90 and don't hammer it hard, the Chevy is probably the cheapest & easiest swap for your situation. (You don't know how painful it was to say that) :lol: :lol: :lol: :lol:

[cdj1676]

ok, that makes since....so if i were to switch trannies, i would need the extra adapters and all that stuff? meaning more money! why so painful?

[LWB]

I'm Mopar through and through!!! (Mopar guys usually don't like admitting anything good about Chevy) :evil: :evil: :evil: :evil: :roll:

[5.0L 44GPW]

Hey Jeepingoat what type of 4.3 are you lookin for carb, EFI, Vortec I will see if I have one, I dont think I do, but I will find you the best deal closest to you on my parts locator :) :)

LWB
The guy that has the 440 CJ5 is the type that never carries spare parts and the thing is a real piece but it always makes it and never breaks, I wouldnt even think of puttin a T90 behind a big block. Also I think you are right about the Chev and T-90 that was a common swap in the jeep pickups and wagoneers. I think I even have a couple of used adapters for that swap Im not sure but you may have to change the input shaft to make up for the inch thick adapter

[cdj1676]

oh...i got ya. so if i said i would rather put in a 390 or a 440, would that make you feel any better?? :D :D
I really dont care what i put in it.......i just want it to be easy! 8)

[thejeepingoat]

something that ran.....i had just did the swap into my jeep, and a bearing was bad, and the guy who sold it to me had put really heavy oil in it to stop the knocking; it lasted ONE DAY of running :evil: ....i have heads, oil pan, oil pump, valve covers, intake, carb., distributor the whole nine, i just need a block with good pistons/rings, cam, timing gear, etc...the rest i have.....thanks a bunch for lookin into it for me

[5.0L 44GPW]

NO NO sorry not the way I wanted it to sound a big block is just way to big for a CJ it doesnt need that much power you are on the right track sorry if we are confusing you, I believe your T -90 is just fine for you with a 350 Chevy for what you are going to do. and it wont be that much money to install. Transdapt also makes a simple motor mount kit for the CJ that bolts or welds in, you are on the right track :D :D :D :D

[jeepxxx]

I know that I am new to your discusion but I have done this and would recomend the small block chevy. I recntly pulled the four out of my 55 M38A1 and put in a 305. I purchased a SM465 tranny for 75 bucks Bought the transfer case to tranny adapter 400 bucks. Youyr mode will be easier because your an inch longer and have a lot more clearance around the headlights. I had to notch my buckets to fit my radiator in(If you don't have a four core I would recomend it,I used on out of a 76 cruiser). Drive line problems can be cured during the istallation process. You can drop your transfer case cross member and weld the new motor mounts down into the frame. As well as some 5 degree shimes under the rear axle. It would be a good idea to box the frame in back to the firewall for extra support(If you build the small block right you can put out some serious torque) but not to far as not to get rid of the twisting that your frame will need to do somme seriuos wheeling.

[LWB]

LWB
The guy that has the 440 CJ5 is the type that never carries spare parts and the thing is a real piece but it always makes it and never breaks, I wouldnt even think of puttin a T90 behind a big block. I hate guys like that!! :x :x :x I always break whatever part I don't carry!!! And cdj was just responding to my staement about Mopar guys not wanting to say anything good about Chevy. (but please don't put in a 390) ;)

[cdj1676]

LWB......... I was just messing around with you about the 390 and 440. I am already sold on the idea of the 350, I just want to make sure I do it right the first time, but like anything else, you have to find the right combo i guess.....thanks

[tomcasino]

I did a 350 swap in a 1981 CJ 5. The original transmission was an SR4. The original engine was a 151 Iron Duke. Since this was a Pontiac engine the 350 bolted right up to the bell housing. Unfortunatly the light duty trans could not handle the power of the built 350. I went through 3 trannys. I then ordered a NP435 transmission. This is a Ford truck tranny. Bulletproof. It bolted up with some minor modifications. It works great. Another note: If you have an AMC 20 rear axle
I would suggest changing the inner drive axles with Mosser one peice flanged axles or similar. The power of a 350 will eventually spin the rear hubs. It's just a matter of time before they break. I hope this will help you.

Mark Tomasino
St. Paul, MN
tomcasino@usjet.net