Chev 350.. possible transmissions

A

allterraintruck

New member
Greetings,

Hello.. Hi I am new. I live up in Washington state.

Okay now for the question.

I bought a 1978 CJ5. It was a project when I got it. Please believe me when I say this. I don't know how to describe it.
Lift with springs only
Dana 60 in the rear
Dana 44 with auto hubs in the front. (with some research, it come from those military dodge trucks)
inline 6. (I changed it from a single barrel to a double barrel) 4 speed manual transmission.
40 inch swampers under it.

Okay, so after working on. I found that the body was completely rusted out. Body mounts are shot. Frame is in decent shape. the list goes on. Today, at a swap meet. I bought a tub, frame and a chev 350 in it.

My question, I am also doing some research online. Will my manual 4 speed fit up to a chev small block 350?

also, in the next few weeks I am going to have parts for sale. But Ill list those in the right forum.

Thank you for your time.

John
 

That all depends! in 78 the factory optional 4spd trans was a T18, very desirable transmission, and strong with a low first gear. You jeep seems to have had many mods done to it, so who knows whats in it now. The inline 6 Is the only factory part you have listed, assuming the "lift with springs only" is a coil suspension. can you post a picture or craw under it and post any numbers you find on the transmission? while there grab a pic of the bellhousing or get the numbers. If its a jeep trans, I believe the jeep cj 4cyl bellhousing will bolt to the chevy 350. Im betting you have a chevy trans currently so that should bolt to your 350.
 
Ive had DECADES of experience with jeeps and GM drivelines. Save yourself a headache on adapting your trannie to the GM small block and look for a Turbohhydromatic 400 (TH400) from a GM bolt up. it is the strongest Auto trannie ever made, bar none, that will fit in a jeep. they will handle over 1 thousand horse in factory configuration. Increasing the size of the trannie cooler above normal (none is used with an manual transmission) and a moderately higher stall speed converter will give you that sudden "jerk" off the line that you get when dumping the clutch, BUT you don't want that when off road. the low speed ability you get with an automatic, when off road. gives you exceptional ability at crawl speed that you simply don't have with a stick. You literally have one foot speed control. When you come to a stop wit a manual, you don't have the ability to simply take your foot off the brake and let the idle speed start inching you forward, like an automatic does. As a side note even Advanced Adaptors recommends this transmission.

PS the TH400 was heavily used in the tow trucks and recovery rigs we depended on to get us out of the mud and swamps we couldn't get out of on our own. Now we need them to use trucks that are 4 times the size to do the same thing.
 
Thanks for the info. I really want to stick with the 4 speed. I'll look for the plate on the side.

I'll post some pictures when I get back home from being on the road
 

An SM 465 will bolt right to your 350 and it is a 4 speed manual with a low first gear. The guy above me who swears about the turbo 400 is right except for one thing, your not doing technical slow crawling with a th400.
 
your crawl is determined by the low range of your transfer case, not your transmission's gearing. The transmission type only determines your ability to control your crawl rate without stalling the engine.
 
i too want a small block chev in my 94 YJ. i want to go hyway speeds AND up the hill to cut fire wood. manual trans. only. ( it has the light duty trans. and tranfer case) this transmission works fine for my use. the small block chev. is something i have and know how to rebuild. I WELCOME any advise. later vin
 

Okay, so tonight I started tearing into the jeep. At first glance it looks like my 4 speed transmission will bolt up to the chev small block. I do have parts for sale if anyone is interested.

20160308_162829.jpg20160308_162829.jpg
 
vinn, just google and read up on it for a few days ahead of schedule to learn what the common issues and pieces you might need can be. i read for a month or two on my 302 swap and didn't have any surprises and it went pretty smoothly. if you prep, it could easily be done in a few weeks, or less. i did mine on saturdays and sundays and it only took a few.

now, my problem is internal engine issues other wise i would be driving mine to and from work. that and helping my son get his cherokee going and motor swapping.
 

Sorry Dragon 5126, you are wrong about that, the lower your first gear is, compounded by your t. case gearing and tire size, determines the final crawl ratio. If you think gearing in your transmission has nothing to do with the final crawl ratio, why don't you put your T case in low, your transmission in 4th gear, and go for it. Here is an example you may understand, a th400's 1st gear ratio is 2.48:1. An SM465's 1st gear ratio is 6.55:1. You may be able to tell by the huge difference is gear ratio's between the two transmissions that the SM465 will crawl slower and have a greater crawl ratio then the TH400, given the same t. case ratio and tire size.
 
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allterraintruck, what plate are you referring to? Did you find out what trans you have now? look for numbers stamped into the side of the transmission, probably on passenger side. post any pictures of the trans. Reason I ask is your axles are GM, your tcase is not stock and has been swapped in, your trans is bolted to a jeep engine, so it could be a jeep trans bolted directly to jeep engine with a adapter for the tcase, or a GM trans adapted to the jeep engine. :if your trans is adapted to the engine, it is highly a GM trans and will bolt directly to a 350. if the trans is bolted directly to the engine, it is probably a jeep trans, and you will likely need a adapter for the 350 to bolt to your current trans, or get a GM trans. You have to determine if you have a jeep, ford, chevy trans now before you no if it will bolt "directly" to a 350. any of them can bolt to the 350 with adapters, but adapter are very expensive.
 
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Did you ever find out what transmission you have? if not can you post any pictures of the transmission so we may be able to identify it.
 
very good info ! thanks. I also want to put a small block in my 94 YJ. my needs are diferent, just want to get rid f that Italian 4 cylinder eng., and be able to get to 70 mph if nessary on the highway. oh - and replace that htdrolic clutch. I have a chev small block, bell housing - clutch etcetera and a couple diferent chev transmissions. vinn at burleydog88@gmail.com
 

Dwillis I don't know how long you have been around but go grab a slide rule, learn how to use it to figure ratios, then sit down and actually look at the final ratios available the low range of a transfer case and the first gear range of any given TH400, and then learn that the TH400 had several first gear ranges, those for trucks and one for automobiles, then come back and explain to all of us how it not having a low enough first gear range made it the auto transmission most used in tow trucks and other recovery rigs as well as why when it was used in the mid Seventies Jeep Cherokee's, a low range was optional since the transmission alone supplied more torque multiplication than the manual transmission with a low range unit did. You need to learn about a device called a torque converter as well. It is very obvious that you are clueless on the very real facts and physics that you are trying to claim superior knowledge on... The fact is NO manual can crawl slower than an automatic due to the fact that you can not stall the clutch forcing torque multiplication, which you can do with an auto. This is why High Stall speed converters and automatics have even taken over the majority of black topped racing applications. But hey you must know more than I do because I only have 40 plus years of real world experience in this
 
He is also ignorant of the fact that an auto has torque multiplication due to the torque converter, and the TH400 had several first gear outputs not just the automobile gearing his limited knowledge covers, and you cant brake/throttle a manual to drive up first gear torque.
 
heatedargument-1.gif


Start a new thread discussing the various setups and their advantages. This really isn't helping the OP as he figured out by himself the transmission he has will bolt up to the small block he just bought.


popcorn-1.gif~c200
 

You would think after 40 years you would have learned something. Slide rule ! lol
 
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