Engine/tranny swap information for 79 CJ7

[tazmaan]

Hi everyone!
I have a 79 CJ7 I have owned for over 20 years. I bought it with the AMC 304 and 3 sp manual (looks like it used to be auto but was converted).
It's seen better days and I happen to have a 92 Chevy k1500 with the 5.3 that I thought about being a transplant (driveline is all good, but body/interior is beat to he77).
I know the chevy is a popular swap, but would I be able to swap anything else? Transmission , tfer case, etc?
Since I am still debating what to do with this truck, figured i'd start here on gathering information about everything I could use from the truck on the jeep, and what I can't.
I do also have two 360 blocks, but condition and completeness unknown. I had just picked them up when a friend was buying a jeep, so no idea if they are trash or useable(rebuildable)
Thanks for any response

Taz

 

[Lumpy Grits]

:ww:

How deep are your pockets?
Remember that the drive shaft in the front has to be on the passenger side.

On the other hand-The AMC 360 is a direct bolt in.
LG

 

[tazmaan]

So you are saying that swapping in anything other than the engine itself would be a very costly proposition?
So engine wise, just an adapter for the chevy to the T-15 (or T-150 ) and maybe an engine mount adapter?
anything else worth considering swapping in?
I have the 360s, but like i mentioned, i havent a clue as to their condition or completeness (got them both for free I believe).

 

[HackFabrication]

...anything else worth considering swapping in?

Slippery slope. If you're not dropping in an identical power unit to what is/was already there, expect costs to escalate. I've seen/read about many different engines, from different manufacturers, in varying sizes, swapped into CJ's. AMC's, Chevy's, Ford's, Chrysler's, Cummin's, on and on. From small 4 cylinder diesels up to blown big blocks. Really depends on budget, skill level, and what you want to fix out in the middle of BFE.

I'd be interested to see what your running gear actually looks like. If you believe it was an automatic originally, then it had the QuadraTrac setup, as that was what AMC put in the 79 CJ7 . You would have an offset rear axle OEM. Take a couple pics of the existing underside and engine bay.

Also: If someone swapped in a manual Transmission , did they swap in a centered AMC20 rear axle along with the Transmission /Tcase (Dana 20 ), etc.? Hopefully it has the same gear ratio as the front. Previous owners tend to be a bit scattered in their thinking process.

A large portion of costs goes to all the 'little things' that are associated with any swap. Things like: Hoses, wiring, radiator upgrade, driveshafts, cross member, engine/Transmission mounts, clutch mechanism, bolts/nuts, exhaust, beer, keeping wife happy, etc. All adds up. The last two items can be quite expensive....

Trust me, I swapped a Ford Racing 5.0L with EFI into my CJ5 . Although with the appropriate motor mounts, it wasn't too complex. But it was far from a drop-in swap. Surprising, even though you will have burnt a lot of gray cells during the 'thinking' phase, what crops up when it starts bolting together.

If you've got a good running GM 5.3L and all the associated wiring, it's definitely a swap worth considering. I'd probably just drop that engine/Transmission in. Adapt the GM Transmission to a Dana 300 and start 'bolting things up'. But also consider this: More horsepower/torque, will wreak havoc with the OEM axles. Especially, if you've got a right foot that's difficult to control. And then there's the problems running larger tires will create.

Once you start modifying things from what the engineers 'thunk out', you are going down the rabbit hole.

 

[Peanut Butter]

Nicely put Hack. What's wrong with rebuilding the AMC 304 ? Bet the cost of that would be much lower than a swap. Be sure to look at the drivetrain like Hack said. The rear end could be a bigger problem than the current engine situation.

 

[Lumpy Grits]

That Hack is 110% 'rite' about the small things that go along with a major driveline swap like that.
The AMC engine swap, would be easy.
LG

 

[tazmaan]

Slippery slope. If you're not dropping in an identical power unit to what is/was already there, expect costs to escalate. I've seen/read about many different engines, from different manufacturers, in varying sizes, swapped into CJ's. AMC's, Chevy's, Ford's, Chrysler's, Cummin's, on and on. From small 4 cylinder diesels up to blown big blocks. Really depends on budget, skill level, and what you want to fix out in the middle of BFE.

I'd be interested to see what your running gear actually looks like. If you believe it was an automatic originally, then it had the QuadraTrac setup, as that was what AMC put in the 79 CJ7 . You would have an offset rear axle OEM. Take a couple pics of the existing underside and engine bay.

Also: If someone swapped in a manual Transmission , did they swap in a centered AMC20 rear axle along with the Transmission /Tcase (Dana 20 ), etc.? Hopefully it has the same gear ratio as the front. Previous owners tend to be a bit scattered in their thinking process.

A large portion of costs goes to all the 'little things' that are associated with any swap. Things like: Hoses, wiring, radiator upgrade, driveshafts, cross member, engine/Transmission mounts, clutch mechanism, bolts/nuts, exhaust, beer, keeping wife happy, etc. All adds up. The last two items can be quite expensive....

Trust me, I swapped a Ford Racing 5.0L with EFI into my CJ5 . Although with the appropriate motor mounts, it wasn't too complex. But it was far from a drop-in swap. Surprising, even though you will have burnt a lot of gray cells during the 'thinking' phase, what crops up when it starts bolting together.

If you've got a good running GM 5.3L and all the associated wiring, it's definitely a swap worth considering. I'd probably just drop that engine/Transmission in. Adapt the GM Transmission to a Dana 300 and start 'bolting things up'. But also consider this: More horsepower/torque, will wreak havoc with the OEM axles. Especially, if you've got a right foot that's difficult to control. And then there's the problems running larger tires will create.

Once you start modifying things from what the engineers 'thunk out', you are going down the rabbit hole.

Tried to take a few pictures where it sits outside, not sure if they will help or not. It stopped raining barely long enough
If it's alot more involved to swap the 5.3 in than rebuilding the AMC 304 or one of these 360s i have sitting around, that's good information to have. I've heard rebuilding engines these days frequently runs quite expensive, which is why I was kicking around the idea of using my truck as a donor.
I appreciate the feedback from you guys.

Thanks

 

[tazmaan]

one last pic, since 5 was the max

 

[Lumpy Grits]

For where you are-I really was think'n the rust would be much worst.
Keep that Flowmaster muffler. It's the only thing that can handle the heat from your 'cat', and not come apart.
Looks to be all OEM driveline right down to the Dana 300 t'case.
LG

 

[tazmaan]

I bought this when living in So. Cal from a jeep place in laguna beach. Where it came from originally before they modded it I have no idea. It hasn't been driven in about 10 years, and the issue the last time I tried to get it running was very bad grinding of the starter/flywheel keeping it from starting. I haven't been able to throw it on the lift yet to try to see what the issue might be.
It's going to be quite awhile before I have time to restore this, the reason I am inquiring about the swap is only because I replaced my truck and before giving this K1500 away or junking it, figured I could use the engine/tranny/tcase/etc whatever else for the poor jeep.
If it doesn't make any sense than I will just get rid of the truck and work with the AMC 304 in it, or the 360 blocks i have if they are salvageable.

 

[Lumpy Grits]

On the ground-Put in high gear and get a couple of friends to help push the Jeep. IGN is to be OFF!!! If you can push it and hear the engine turn-That would be good indication of the engines status.
Don't do anything, till you have confirmed all fluid levels.
Why do you feel the traqnny was an auto?
Your VIN# will tell you what it was built with.
LG

 

[tazmaan]

Am pretty sure engine is fine, as I did have it running for a day. A long time ago it was probably in need of a refresh, but it would always run pretty strong. It's the inability to start it due to whatever is going on with the flywheel or other possibilities that keeps it parked. If it IS the flywheel broken, I wasn't sure of how in depth a job that is to replace.
Sounds like the theme of the thread thus far is to not bother with the 5.3, so maybe i outta just put that up for sale at a give away price and be done with it.

The fact that the steering column has the location for the auto shifter is why I thought it had an auto originally, or at some point before the Jeep place converted it.

 

[Lumpy Grits]

Pull the starter and see if you knocked teeth off the flywheel starter gear.
How old is this gas your using?
How old is the battery?
Try a NEW good battery.
AGAIN-post your VIN # as that will tells us what it came with.
LG

 

[tazmaan]

Interesting, per the VIN it is a 3 sp manual. Wonder why the auto shift spot in the steering column? Anyhow, a long time mystery solved I guess

 

[Lumpy Grits]

OP wanted a tilt colume I bet.
LG

 

[Peanut Butter]

Tried to take a few pictures where it sits outside, not sure if they will help or not. It stopped raining barely long enough
If it's alot more involved to swap the 5.3 in than rebuilding the AMC 304 or one of these 360s i have sitting around, that's good information to have. I've heard rebuilding engines these days frequently runs quite expensive, which is why I was kicking around the idea of using my truck as a donor.
I appreciate the feedback from you guys.

Thanks

Just saw these. Looks like a Dana 20 TC. The rear axle does not have an off-set pumpkin. Dana 30 front axle. Lots of rust.

Just some advice here take it for what it is worth (2 cents maybe). I would be more concerned about seals and bushings, bearings, fluids, brakes, and the really bad rusted stuff first. Worry about a different engine some other time. Putting it back into working order with what's in it is not a bad choice. Those components will allow you to do all kinds of wheeling and driving. Concentrating on removing and replacing the worn components will make for a much better Jeep. Putting the best engine and drivetrain possible in it will not be worth a darn if all the other stuff needs some work too. You can read through my rebuild of my '79 CJ7 . I started over 5 years ago. A complete rebuild is not an easy task. Replacing worn parts and being able to drive it at the same time is a lot more fun. Get the engine running, get it drivable, and then concentrate are one area at a time. I guarantee you'll have more fun that way, and you'll also get a feel for what direction you want to go with upgrades.

 

[Lumpy Grits]

Forgot the D/20 t'case was used till 1980
After look'n on a larger screen. PB is again, 110% 'rite'.
Sorry for the misinformation on my part.
LG