Would like to install gm 4.3l v6 and th700r4 in my cj7.. What are costs? Issues?

[76cj7chick]

Hey all jeepers...
So to make a long story short.. Had to remove the tranny and engine for some repairs (flexplate and motor mounts replacement) but now that they have been removed from the jeep.........I've been thinking....and... I REALLY want to install a rebuilt/reman gm 4.3l v6 with th700r4 automatic Transmission into my 76 CJ7 jeep... I hope to retain my dana/spicer 20 tcase, as I've heard they are tough and easy to rebuild...
So far the issues I see.. Cost... And cost...

But seriously.. I already have the (1987-1991) chevy tbi throttle body and fuel components on my jeep... But not the engine to go with it...

Could everyone chime in (especially those who have done the swap) WITH pictures and let me know the good, bad and ugly of this swap BEFORE I go forward?
Also, where can I buy an engine and Transmission for an economical price...
Is it better to get a "Complete" engine and Transmission so I don't have to put pieces together or is it "cheaper" to buy the parts separately?

Please let me know all of the issues.... Also, could I get someone to tell me where the engine will be mounted on the frame and mounts?

 

[Old Dog]

I don't have a 4.3 but I do have a 350, same thing only longer.
The biggest headache is all the little stuff like brackets. You also might need a new rad. as the hoses hook up different.
This swap has been done a lot so there should be plenty of info out there.
Advance adapters or Novak are good for both info and parts.
I think the best part of the 4.3 is that it's short and can be moved forward farther than a v-8. We cj'ers need all the room we can get.

If I was you I would get the engine/Transmission /wiring all together from the same truck.

 

[76cj7chick]

I don't have a 4.3 but I do have a 350, same thing only longer.
The biggest headache is all the little stuff like brackets. You also might need a new rad. as the hoses hook up different.
This swap has been done a lot so there should be plenty of info out there.
Advance adapters or Novak are good for both info and parts.
I think the best part of the 4.3 is that it's short and can be moved forward farther than a v-8. We cj'ers need all the room we can get.

If I was you I would get the engine/Transmission /wiring all together from the same truck.

Thanks for your response... Would you have any pictures of your build? How far do the mounts reach out in the engine bay? It appears the po installed some different mounts in my CJ7 to accommodate the length of the amc GM Turbo 400 and the off set driveshafts on the Dana 20 tcase.. (Both of which were out of a fsj truck.. At least that is what the tag read. )
I agree... LOVE the idea that I will be able to move the "wider" but shorter v6 forward in the engine bay as I felt the po moved the AMC 258 i6 / 4.2l /amcth400 too far forward.. Barely giving me any radiator room... So, the engine and tranny are now for sale... I am still torn on whether to buy a rebuilt engine and tranny and adapter and other little parts or just get a used blazer.. I just don't like removing engines and transmissions.. So, partially looking for a rebuild.. Anyone have experience/ pictures on which way they went.. If yes, please share...

Also, I've been seeing a lot of 350 engine swaps.. Do they also come with the th700r4? Is the gas mileage much different between the two?

Thanks again for your help...

 

[76cj7chick]

Anyone with pictures of the swap progression?

Here is a picture of my CJ7 . Will these mounts work? Or will I have to get some from novak or advance adapters?

 

[Hedgehog]

I've always thought one of the nice things about a V6 engine swap was the fact that the V6 is shorter than most other engines. This allows the Transfer Case to stay where it is allowing you to leave the drive shafts alone and use the rear Transmission /Transfer Case mounts alone. Leaving with only the motor mount locations to deal with. I suppose that doesn't seem like much help, but every little bit helps.

 

[tarry99]

Anyone with pictures of the swap progression?

Here is a picture of my CJ7 . Will these mounts work? Or will I have to get some from novak or advance adapters?

Your mounts will work as a base for the conversion mounts by either Novak or A/A........As far as the 4.3 , keep in mind the 700R4 is a 4-speed with 30% Overdrive in 4th..........Not knowing what axle gear ratios you have may not be to the liking of an under powered V6 with tall gears.
Dana 20 Transfer Case is no issue.

I would be looking to buy a complete motor with tranny & harness. The later motors would have a 4L-60 behind them........same tranny but electronic shifted.

Not really a cheap conversion as in most cases a takeout may need the motor , tranny or both rebuilt..........New Wiring ,different shifter, new drive-lines and mounts as the 700R4 is over 23" long , Radiator, cooler, exhaust , floorboards and tranny cover and as mentioned above perhaps a gear change............Been done many times.......do your homework first!

 

[76cj7chick]

Your mounts will work as a base for the conversion mounts by either Novak or A/A........As far as the 4.3 , keep in mind the 700R4 is a 4-speed with 30% Overdrive in 4th..........Not knowing what axle gear ratios you have may not be to the liking of an under powered V6 with tall gears.
Dana 20 Transfer Case is no issue.

I would be looking to buy a complete motor with tranny & harness. The later motors would have a 4L-60 behind them........same tranny but electronic shifted.

Not really a cheap conversion as in most cases a takeout may need the motor , tranny or both rebuilt..........New Wiring ,different shifter, new drive-lines and mounts as the 700R4 is over 23" long , Radiator, cooler, exhaust , floorboards and tranny cover and as mentioned above perhaps a gear change............Been done many times.......do your homework first!

There was a time when I thought I'd like to get a rebuild or reman engine and tranny but after further research I have decided to try to find a decent used chevy truck or suv.. The idea of trying to find all of the parts for a "naked" motor seemed daunting.. I like the idea that I can get a vehicle that will have most of the parts just to swap over..

Yes, according to Novak the th700 is just over 29" and my amc GM Turbo 400 is 27" with the tcase.

What years of chevy's would you recommend to find the electric 700r?

Sounds like The v6 may be too weak for my axles and jeep (Hmm.. Me) Should I look for a 350 instead? If yes, which liter? Also, does it come with a Overdrive Transmission ? Will it just bolt up to the Dana 20 tcase?

Thanks for your suggestions and positive words.

 

[76cj7chick]

I think I will look for a used vehicle that has all... Well most of the parts I will need for the swap..

Looks like separate from the vehicle-- I will need the tranny to tcase adapter.. Would Novak be the only option? They are just shy of $700...
And then I would need to get a pair of conversion motor mounts.. $200..
Is there anyway I can keep my radiator and just use different hoses to route them to my 4.3 engine? If not, I may be looking at $100-300 for that.. How much could I expect to pay for a decent running chevy with the correct engine and tranny?

Thanks guys for your help.

 

[Hedgehog]

No matter what you are going to spend a minimum of a couple thousand dollars for what you are proposing to do. Expensive ... Yes it is. Worth it ... maybe yes, maybe no. Please tell us again, what was wrong with your original engine/Transmission . set up?

 

[Bent]

why not use a chevy GM Turbo 400 and just swap the factory adapter off the AMC GM Turbo 400 ? By the way, are you sure your GM Turbo 400 isn't set up for a QuadraTrac ? The adapters look similar, but the QuadraTrac will have a lot more shaft sticking out. I think there might be front driveline to Transmission oil pan clearance issues with the 700r4 and the compact jeep transfer cases.

 

[Kane]

I think I will look for a used vehicle that has all... Well most of the parts I will need for the swap..

Looks like separate from the vehicle-- I will need the tranny to tcase adapter.. Would Novak be the only option? They are just shy of $700...
And then I would need to get a pair of conversion motor mounts.. $200..
Is there anyway I can keep my radiator and just use different hoses to route them to my 4.3 engine? If not, I may be looking at $100-300 for that.. How much could I expect to pay for a decent running chevy with the correct engine and tranny?

Thanks guys for your help.

I actually did this. I found a CJ5 that had a sweet frame and a 350 conversion tied to a T-18 . I bought it for $3200 then swapped my body and all my good parts over to it. I put the body and parts on my old frame and sold the jeep for $3000. Walla. 350 conversion. For $200 and sweet equity plus the rust free frame.

 

[tarry99]

There was a time when I thought I'd like to get a rebuild or reman engine and tranny but after further research I have decided to try to find a decent used chevy truck or suv.. The idea of trying to find all of the parts for a "naked" motor seemed daunting.. I like the idea that I can get a vehicle that will have most of the parts just to swap over..

Yes, according to Novak the th700 is just over 29" and my amc GM Turbo 400 is 27" with the tcase.

What years of chevy's would you recommend to find the electric 700r?

Sounds like The v6 may be too weak for my axles and jeep (Hmm.. Me) Should I look for a 350 instead? If yes, which liter? Also, does it come with a Overdrive Transmission ? Will it just bolt up to the Dana 20 tcase?

Thanks for your suggestions and positive words.

After about 1993 for the 4L-60e Electronic.........that tranny has to be matched with a similar year motor and ECM system........Not to say the V6 will not work.......again research is the key when picking engine combinations for a project. Horsepower & Weight of the donor vehicle vs yours Jeep is where to start to understand whether or not the donor has the torque needed to do the work for your application..........gear ratio's as mentioned also need to be correct to get that work done............Nothing wrong with the earlier 700R4 manual shift trannys , a little less complicated than the later versions.....just depends on what the goals for the built are and what donor components are being used. And yes a complete running vehicle makes a nice donor.

Not one single project is going to be the same. So plan on the unplanned! There is no swap that cannot be done........it really boils down to the knowledge and determination of the builder...... Hopefully you have additional support near you and access to a shop and the tools required. Not everything will Bolt on.........there will be allot of fab work.

Take a step back and see if you really have what is required to complete such a project..........It will be fun but not easy!

Here is one of my builds with this combo going into a 65-CJ6 105" WB / Wrecked 1990 Corvette donor 5.7 250HP 350 ftlbs of torque. Basic TPI ECM system......The reason for the choice? Corvette donors and all there brackets and exhaust are neatly tucked in close to the motor , just what a Jeep needs. This vintage motor has huge low RPM torque numbers right off idle via the long runner TPI system , Just what you want for low speed cruising.....Early basic TPI ECM system gives you less wiring and sensors to mess with while still having all the things that are important to a Jeep both on and off the road......This will also use a 700R4 manual shifted tranny shown in one of the photos.

Hope all this helps!

 

[76cj7chick]

I actually did this. I found a CJ5 that had a sweet frame and a 350 conversion tied to a T-18 . I bought it for $3200 then swapped my body and all my good parts over to it. I put the body and parts on my old frame and sold the jeep for $3000. Walla. 350 conversion. For $200 and sweet equity plus the rust free frame.

That's a good idea too.. :drool:

 

[76cj7chick]

After about 1993 for the 4L-60e Electronic.........that tranny has to be matched with a similar year motor and ECM system........Not to say the V6 will not work.......again research is the key when picking engine combinations for a project. Horsepower & Weight of the donor vehicle vs yours Jeep is where to start to understand whether or not the donor has the torque needed to do the work for your application..........gear ratio's as mentioned also need to be correct to get that work done............Nothing wrong with the earlier 700R4 manual shift trannys , a little less complicated than the later versions.....just depends on what the goals for the built are and what donor components are being used. And yes a complete running vehicle makes a nice donor.

Not one single project is going to be the same. So plan on the unplanned! There is no swap that cannot be done........it really boils down to the knowledge and determination of the builder...... Hopefully you have additional support near you and access to a shop and the tools required. Not everything will Bolt on.........there will be allot of fab work.

Take a step back and see if you really have what is required to complete such a project..........It will be fun but not easy!

Here is one of my builds with this combo going into a 65-CJ6 105" WB / Wrecked 1990 Corvette donor 5.7 250HP 350 ftlbs of torque. Basic TPI ECM system......The reason for the choice? Corvette donors and all there brackets and exhaust are neatly tucked in close to the motor , just what a Jeep needs. This vintage motor has huge low RPM torque numbers right off idle via the long runner TPI system , Just what you want for low speed cruising.....Early basic TPI ECM system gives you less wiring and sensors to mess with while still having all the things that are important to a Jeep both on and off the road......This will also use a 700R4 manual shifted tranny shown in one of the photos.

Hope all this helps!

Wow! Thanks. Nice pictures...
Is that a custom jeep frame I see in the last picture? :drool:
How long do you think it would take for a newb.. AKA "slower" person to do the swap of the engine and Transmission -Once they get the vehicle to swap the middles? A weekend or week?

Also, I believe my axles are the stock from 76 for CJ7 jeep. Rear is the Dana 20 and front is Dana 30 .. Doesn't look like they were upgraded.. Can't find any numbers on the axles..

 

[tarry99]

Wow! Thanks. Nice pictures...
Is that a custom jeep frame I see in the last picture? :drool:
How long do you think it would take for a newb.. AKA "slower" person to do the swap of the engine and Transmission -Once they get the vehicle to swap the middles? A weekend or week?

Also, I believe my axles are the stock from 76 for CJ7 jeep. Rear is the Dana 20 and front is Dana 30 .. Doesn't look like they were upgraded.. Can't find any numbers on the axles..

What always seems like it should only take an hour , sometimes takes several or even a day..........More than likely the Donor Motor and Tranny will be in and out of the vehicle several times.........not something you can rush so again plan on some patience.............even with all of the goodies at your finger tips it's still a few days...........If this was just an R/R of your current motor & tranny for a replacement of the same type it's a weekend.
The Dana 30 up front can be a decent axle with after market axles as long as tire size is kept to about 35".........the rear axle I assume is a corporate AMC and they too can be built stronger with similar upgrades.......gear ratios again you need to see what you have.

Your doing everything right .............continue asking questions, make a plan, understand the options , and outline to yourself what is the ultimate goal that your trying to obtain?
Again these projects are not easy.

 

[76cj7chick]

What always seems like it should only take an hour , sometimes takes several or even a day..........More than likely the Donor Motor and Tranny will be in and out of the vehicle several times.........not something you can rush so again plan on some patience.............even with all of the goodies at your finger tips it's still a few days...........If this was just an R/R of your current motor & tranny for a replacement of the same type it's a weekend.
The Dana 30 up front can be a decent axle with after market axles as long as tire size is kept to about 35".........the rear axle I assume is a corporate AMC and they too can be built stronger with similar upgrades.......gear ratios again you need to see what you have.

Your doing everything right .............continue asking questions, make a plan, understand the options , and outline to yourself what is the ultimate goal that your trying to obtain?
Again these projects are not easy.

Hmmm.. This may be a stupid question but... How do I tell what gear ratio I have?
Will it be stamped or have a tag on the axles that indicate the gear ratios?
My tires are 31" so they are babies compared to the 35"
Yes, the rear axle is AMC20 .. It is also centered.

Thanks Tarry99 again for your help!

 

[tarry99]

Hmmm.. This may be a stupid question but... How do I tell what gear ratio I have?
Will it be stamped or have a tag on the axles that indicate the gear ratios?
My tires are 31" so they are babies compared to the 35"
Yes, the rear axle is AMC20 .. It is also centered.

Thanks Tarry99 again for your help!

76 No Problem Glad to help!

There are many methods........If your lucky a tag may still be on the axles under a pair of cover bolts.......in lieu of that , the easy way at least for me is to drain the oil in the rear or front axle which ever is easiest and count the teeth on the ring and pinion gears........divide them into each other and you'll get the gear ratio...........Of course well assume that you have had it in 4-WD before and both axles are the same ratio? (And I only say that as I have seen dummies change used axles with different ratios!)........
Some folks will also jack up the vehicle and crawl under and count the drive shaft revolutions versus the tire revolutions.........not and exact science method but better than a guess. Google that up and I'm sure you'll find other methods on line.

I only mentioned the 35" tires as a potential Max for the Dana 30 and the AMC20 without additional work...........

 

[76cj7chick]

76 No Problem Glad to help!

There are many methods........If your lucky a tag may still be on the axles under a pair of cover bolts.......in lieu of that , the easy way at least for me is to drain the oil in the rear or front axle which ever is easiest and count the teeth on the ring and pinion gears........divide them into each other and you'll get the gear ratio...........Of course well assume that you have had it in 4-WD before and both axles are the same ratio? (And I only say that as I have seen dummies change used axles with different ratios!)........
Some folks will also jack up the vehicle and crawl under and count the drive shaft revolutions versus the tire revolutions.........not and exact science method but better than a guess. Google that up and I'm sure you'll find other methods on line.

I only mentioned the 35" tires as a potential Max for the Dana 30 and the AMC20 without additional work...........

I checked to see if i could locate any tag or number on either of the diffs. I found one on just the front diff.. (Tag reads: 5354908 3 54 & 46-13) I don't know what that means. Would you?
And then, I searched through old pictures of when I changed the gear oil and diff covers. I found a few pictures. Could you tell by the pictures what gear ratio the rear is? And if the front matches the tag?
THANKS AGAIN for your help!

If the front diff tag is correct, according to the internet, the front gear ratio is 3.54 (what ever that means.) :0

 

[Hedgehog]

3 54 & 46-13 ....... 46 (teeth on the ring gear) divided by 13 teeth on the pinion gear = 3.5385 or 3.54

3.54 gears are a very nice intermediate gear. Where a 4.11 gearing is an off road or drag racing or power gear. A 2.73 (found in newer CJ's) is a road gear or a gear generally found in a family car. At any given speed a 2.73 geared vehicle will run at much lower RPM's than a 4.11 geared vehicle. It's easy to see where a 2.73 geared vehicle will generally give higher/better mileage than a 4.11 geared vehicle. Also, a 4.11 geared vehicle will have more power or will pull better than a 2.73 geared vehicle. Naturally both axles should have the same gearing and a 3.54 gear set is was very common in your vehicle year.

I hope this helps.

 

[Kane]

Hedgehog is pretty much on point with his description. I like 3.54 or 3.73 gears for 33 inch tires and road use. The ratio means this. The drive shaft will turn 3.54 times for every revolution of the wheel. So 4.11 gears will have the shaft turn 4.11 time per one of the wheel. this means the rpms of the motor will be higher.