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Hagerty
Hagerty Employee

Jeep Grand Wagoneer LS swap: Project accomplished, lessons learned | Hagerty Media

It's done. It's finally done. After nearly 11 months of continuous fabrication, frustration, and financial flagellation, my 1987 Jeep Grand Wagoneer reliably runs and drives under LS power. I've spent so much of this series talking about what went wrong along the way to swapping my perfectly functional AMC 360 for a 5.3-liter LS V-8 that I thought I'd open this project wrap-up by highlighting the positives.
https://www.hagerty.com/media/maintenance-and-tech/jeep-grand-wagoneer-ls-swap-project-accomplished-...
16 REPLIES 16
Flashman
Advanced Driver

Per ardua ad astra. I'm glad you stuck with it and wrote so engagingly about it. Happy motoring.
Maestro1
Detailer

Well done. It's a wonderful idea to begin with, and I hope you enjoy it to the fullest.
greenhue
Pit Crew

I own a 1970 AMC Javelin that is on its 3rd motor, a 401 with a 727, donated from a 1972 Grand Wagoneer, that has taken me down the upgrade road. I didn't know 401s wouldn't mount to the Borg Warner transmission, so $1700 later, the 727 was installed. You learn as you go but to spend $15000 for a better engine and better mileage, it is not the road I want to take. My car has a 2 hour range, 16 gallon tank at 80 mph equals 2 hours driving time. Many have taken the LS route and are very happy with it, but most have said the soul of the car is gone. To each his own, but as long as you drive it, how you spend your money is your choice. Happy New Year and drive your classic.
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OldCarMan
Advanced Driver

IF you had invested the same time and effort to build a good AMC or Chrysler engine, you would have saved a lot with NO loss of performance. The problems encountered were of your own making. I'm glad you were finally able to sort them out, but I have to ask: What were you thinking when you started? That should be the lessons learned.
PlumCrazyChris
New Driver

Not sure you read it all..... 400 HP and 3x the gas mileage! That's huge! Like I said previously, I think that gain is primarily from the overdrive transmission though.
BenjaminHunting
Pit Crew

OldCarMan - my first post in this series lays out the decisions that lead to the swap, but as Chris mentions, 400 horsepower plus fuel mileage in the high teens / low 20s is not possible with a built AMC engine. It's also worth noting that a high horsepower AMC motor is going to be a lot less comfortable to drive and maintain on the street compared to a similarly-powerful LS setup.
Aquay_Mizmo
Intermediate Driver

Whoa, you talked me out of a LS swap I was thinking of doing. Thanks for sharing.
Smasher
New Driver

I wonder what a good rebuild of the AMC 360 and fuel injection would have yielded in performance and gas mileage. The LS is still just a push rod motor with fuel injection.
I have heard this story from many a (financially) poorer car owner.
Geok86
Advanced Driver

Everyone seems to want to LS EVERYTHING, but as you found out (the hard way), it’s not as easy as people think it is/make it out to be....I would do an LS for a street/strip vehicle, because they are plentiful, and with forced induction...they produce A LOT of reliable power!
PlumCrazyChris
New Driver

Smasher : from the factory, both the 360 and the 258 got only 12 mpg in the Grand Wagoneer. I never got better than that with my Cherokee's either. I sold my 360 79 Cherokee due to the mileage and bought a 83 Cherokee with a TBI 258 with a HO 4.0L headswap, and although it was very crisp and powerful as the 360, it still got only 12 mpg. The real upgrade I think it the 4L60 transmission.

I swapped a hemi and A518 overdrive trans in my 70 Challenger and it runs great. But I think its mostly due to the overdrive trans. I could have stuck with a hot smallblock, thrown efi on it and it would have been just about as effective as the hemi, and just as fun to drive, but cost only a fraction of the hemi swap.

farna
Detailer

You could have easily rebuilt the AMC 360 and upgraded it with something like a FAST EZ-EFI (or other EFI system) and had a vast improvement. That would still leave you with having to change the transmission to a modern OD trans (AMC to GM adapter?) or installing a Gearvendors OD unit (expensive... may as well do the 4L60E swap! Would be a bit more, but...). It may not have netted quite as much power or gas mileage as the LS swap (depending on upgrades), but would have been close. Probably cost as much too though. I'm an AMC guy, but there are limits to what you can do with old tech, and adding bits of new tech to old tech doesn't always have as good a result as just swapping in new tech. I considered building a GW as my camper tow vehicle, but I'd have had to upgrade the towing capacity significantly as well. Doing all the work myself and swapping a late model V-8 (thinking Toyota 5.7L, Chrysler 5.7L, or Ford 5.4L/5.8L... 5.3L/6.0L/6.2 GM LS models were on the bottom of my list, but if one came along at the right price...). I figured I'd have at least $10K (more likely $12-15K!) in it when done, and still have some "old car issues" to deal with along the way. I decided I'm just not that in love with the GW to put that kind of money into what would have likely ended up being a body swap to the truck/SUV I bought for the engine, though I may have kept the GW frame, or parts of it (could cut it and the donor and do a front frame clip...). I'm capable, and have a shop, but time would be an issue. I built my 63 Rambler Classic wagon as a (literal!) daily driver (4.0L/AW4/Jag IRS) back in 2003 over the course of a year... mostly. Still had some niggling little issues to work out over ensuing years. I rushed that job some, but it all worked out. Some things could be more polished, and I've worked on those over the years (still drive it, just no longer a daily driver). In the end I decided I just didn't want that big a project for something I didn't REALLY love, so bought a used Ford Expedition. Stumbled on a 2005 a couple years ago that looked 7-8 years old instead of 15 -- very well taken care of and 99K miles. Got it for a good price, and a little maintenance later (and an unexpected trans rebuild 3-4 months after buying!) I have a prefect tow vehicle. Still a niggling little issue or two to work out, but it was ready to go right away. You must REALLY love the GW to do what you did... like I did/do my Rambler.
BenjaminHunting
Pit Crew

It's very possible to build the 360 for power, but a 400 horsepower 360 isn't going to offer the street manners or the fuel efficiency of a 400 horsepower LS, nor will it be as easy to maintain. These were major factors in me choosing to do the swap.

I thought long and hard about many of the different strategies you mention here before I made my decision - it looks like we had very similar ideas about how to improve the GW. You're definitely right htat you really do have to love it to go whole-hog with it as a platform. Buying a more modern SUV as a tow vehicle would have by far been the most logical decision for me to make.

I'd love to hear more about your 4.0 Rambler Classic wagon, that sounds amazing.
farna
Detailer

What, no pic of the LS engine sitting in the completed vehicle???
BenjaminHunting
Pit Crew

If you scroll through the gallery, it's there.
drjim
Detailer

Well done! It's always a good feeling when I see a person actually finish a project of this magnitude.
Allen
New Driver

Please to see the honesty in this review of the project to date. To many times intentionally or not people don’t talk about the surprises found and unexpected $$$ spent to rectify them. Sharing these things help others avoid the same pitfalls and set realistic expectations instead of becoming frustrated and giving up on completion of their project.