Recently picked up a ‘72, thinking of doing an LS swap. I’d like to be able to cruise on the freeway but wondering how the original 3-speed will do with the factory axles and 33’s? I’d like to go with a 5-speed (NV4500, H55f, AX15) but not sure if the cost is worth it to get the overdrive. I know the NV4500 is also longer which makes for a short rear driveshaft (potential vibration), and both diffs being offset means either an Orion t-case or a split case behind the H55f. Is there a “best” combo to stay manual, have good drivability, and not break the bank?
LS Swap
- Thread starter 85fourunner
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I have a more or less stock 72 with 3 on the floor since 82. It did ok when the speed limit was 55. Above about 65 it sounded like it was going to throw a rod and it felt like it as going to fly or swap ends - spooky is an accurate term. I drove with my hands low on the wheel and braced against my knees.
My plan was to hand build a 283 Corvette engine (for RPM's). I scored a Toyota 4 speed with the Advance Adapter bell housing for the sbc. I was going to mate my 3 sp tranny's transfer case to get the lower crawl gear in low range low. No overdrive but at least synchro's.
I like the NV4500 or perhaps some sort of 6 sp. Longer tranny moves engine forward to get the sbc out of the fire wall where it needs to be anyway. The Toy 4 sp is longer too but not as much.
Not a slop bucket tranny guy at all. Not into fuel injection either. Not a fan of aluminum heads or blocks. Old School.
There are programs/apps to help you model the effects of "rubber overdrive" larger tires, swapping rear end ratios and gears in the tranny - or just do your own in a spread sheet.
If I was a rock crawler type the Orion would be the ticket.
I have a Suzuki 300 king quad. 5 speed forward primary plus reverse that has 2H, 4H, 4L, and 4 Super Low plus a rear differential lock. Lots of gears and I have used them all.
My plan was to hand build a 283 Corvette engine (for RPM's). I scored a Toyota 4 speed with the Advance Adapter bell housing for the sbc. I was going to mate my 3 sp tranny's transfer case to get the lower crawl gear in low range low. No overdrive but at least synchro's.
I like the NV4500 or perhaps some sort of 6 sp. Longer tranny moves engine forward to get the sbc out of the fire wall where it needs to be anyway. The Toy 4 sp is longer too but not as much.
Not a slop bucket tranny guy at all. Not into fuel injection either. Not a fan of aluminum heads or blocks. Old School.
There are programs/apps to help you model the effects of "rubber overdrive" larger tires, swapping rear end ratios and gears in the tranny - or just do your own in a spread sheet.
If I was a rock crawler type the Orion would be the ticket.
I have a Suzuki 300 king quad. 5 speed forward primary plus reverse that has 2H, 4H, 4L, and 4 Super Low plus a rear differential lock. Lots of gears and I have used them all.
This one is my favorite; have used it many times. It has a gazillion transmissions and some transfer cases already input, in drop-down menus:
Gear Ratio Calculator - https://www.grimmjeeper.com/gears.html
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- #4
Thanks!
If you stay Toyota 3 speed just swap the diffs to 3.73 and roll on.
My 5.3 4 speed 40 will run as fast as you want to drive it. It’s very comfortable engine wise at 65mph on 35” tires and 4.11.
33s and 3.73 would be pretty much the same.
H55F is the most documented, and quite possible the easiest as you can source a brand new trans and transfer case combo from many vendors.
I 1000% do not regret my LS swap. It has made my 40 my favorite vehicle to drive. Mine gets drove daily, starts like a 2020, has enough power to be scary, yet is completely refined engine wise. Highly recommend if you are not a purist and plan on driving yours.
My 5.3 4 speed 40 will run as fast as you want to drive it. It’s very comfortable engine wise at 65mph on 35” tires and 4.11.
33s and 3.73 would be pretty much the same.
H55F is the most documented, and quite possible the easiest as you can source a brand new trans and transfer case combo from many vendors.
I 1000% do not regret my LS swap. It has made my 40 my favorite vehicle to drive. Mine gets drove daily, starts like a 2020, has enough power to be scary, yet is completely refined engine wise. Highly recommend if you are not a purist and plan on driving yours.
There's no best "combo", it really depends on what you want to do with your 40. As others have said, you can keep your 3 speed or swap to the more refined 4 speed and go to 3.70:1 3rds, or adapt a 5 speed along with playing around with 4.11 or 3.70 3rd members. Tire size plays too. Use an rpm calculator and enter your a actual tire size, not the advertised size, so you can see rpms at highway speeds.
I make a chart for each driveline I'm considering for crawl ratios for offroad. I put the individual trans gear ratios across the top, 1st thru 4th or 5th, and vertically the various tcase ratios for offroad for each driveline.
On my 40, the PO had a sbc with a 1st gen NV4500 and 1 piece tcase installed. It is an early conversion and I think the driveline conversion is longer than what AA offers today. My driveshaft is short, but I don't get any vibration. I'm setting it up to be primarily street driven and trail capable. I Initially put 3.70 3rds in it which put my rpms around 1800 at 65 mph. I found with 33x10.50's it was marginal and knew I would eventually would get 35's, so I reinstalled 4.11's and run around 2050 with the 33's. It offers better drivabilty and eliminates a lot of down shifting on steeper hills.
I've looked at the 5 speeds you mentioned along with the various tcase setups to put behind them. The 1st gen NV4500 has around 6.54 1st gear, the later ones are around 6.34. They all have 27% reduction in 5th gear. The h55f and the ax15 5th gears are around 20%. Imo i think, the 27% reduction works better with the V8, but not so much with the stk 6 cylinder. The 1 piece tcase has an anemic reduction of 1.99:1. I think there is 4:1 gears available for it, but imo that's too much. 3:1 would be better. I think an Orion with lower gears is really expensive for not much benefit. The 2 setups I'm considering upgrading to is using my NV4500 with the stronger splitcase with lower gears, or i would most likely go with a Dana 300 with its' stk 2.62:1 gear reduction and center my stk 40 rearend. The latter has a lot of upgradable options available.
I make a chart for each driveline I'm considering for crawl ratios for offroad. I put the individual trans gear ratios across the top, 1st thru 4th or 5th, and vertically the various tcase ratios for offroad for each driveline.
On my 40, the PO had a sbc with a 1st gen NV4500 and 1 piece tcase installed. It is an early conversion and I think the driveline conversion is longer than what AA offers today. My driveshaft is short, but I don't get any vibration. I'm setting it up to be primarily street driven and trail capable. I Initially put 3.70 3rds in it which put my rpms around 1800 at 65 mph. I found with 33x10.50's it was marginal and knew I would eventually would get 35's, so I reinstalled 4.11's and run around 2050 with the 33's. It offers better drivabilty and eliminates a lot of down shifting on steeper hills.
I've looked at the 5 speeds you mentioned along with the various tcase setups to put behind them. The 1st gen NV4500 has around 6.54 1st gear, the later ones are around 6.34. They all have 27% reduction in 5th gear. The h55f and the ax15 5th gears are around 20%. Imo i think, the 27% reduction works better with the V8, but not so much with the stk 6 cylinder. The 1 piece tcase has an anemic reduction of 1.99:1. I think there is 4:1 gears available for it, but imo that's too much. 3:1 would be better. I think an Orion with lower gears is really expensive for not much benefit. The 2 setups I'm considering upgrading to is using my NV4500 with the stronger splitcase with lower gears, or i would most likely go with a Dana 300 with its' stk 2.62:1 gear reduction and center my stk 40 rearend. The latter has a lot of upgradable options available.
Good advice above. I also love my LS. I have a 6.2l and I just got back from a long weekend trip. I put about 500 miles on it and averaged 13 mpg (12-14), which isn’t bad considering that mine weighs 6k pounds with 40” tires, and I was going the speed limit up I-70 (6% grade at 65 mph, and still getting passed!).
The 6.2l is fun but the 5.3l is probably plenty of power, even for my setup. I went with this size because I pull a camper but I can’t use all of my power when pulling up a long grade as the engine gets hot, even with a huge radiator. I may consider a BMW diesel in my next Cruiser. I’d love to get 20-25 mpg.
The 6.2l is fun but the 5.3l is probably plenty of power, even for my setup. I went with this size because I pull a camper but I can’t use all of my power when pulling up a long grade as the engine gets hot, even with a huge radiator. I may consider a BMW diesel in my next Cruiser. I’d love to get 20-25 mpg.
I'm partial, put a LS 6.0 ( early 2000's) and never look back. That LS has been worthy of the Land Cruiser, I was hesitant to go with a comp controlled motor, took Jack Rice 6 years to convince me they were trust worthy. I have an sm420, 4:1 Orion, 4:11's on 38's and I have to say, low range, 3rd gear is sooooooo fuuuuun, from idle/crawl to bouncing off the limiter, love it.
- Thread starter
- #10
I’m leaning towards the LS for that reason, drivability! I don’t mind getting 12-15 mpg if it has plenty of power, and it sounds like the F motor will have the same mpg with barely enough power.
Just in case you need to read a bunch of random wondering and eventually an LS swap.
FloridaLife
SILVER Star
I have a '71 FJ40 that I am eyeballs deep into redoing. I won't bore you with the details but it turned out to be a disaster in disguise, more on all that in my thread New to the FJ40 Scene.
Here is some info that may help you:
After buying it and a 2F drivetrain with a 4 speed manual and a mechanical overdrive unit, in December I unfortunately had my 6th spine surgery, my 4th in my low back. And, 41 years ago I had surgery on both hips. So, my wife kept pushing me to change my game plan and put an automatic transmission in it because she was worried that all the clutching and shifting, especially when caught in stop & go bumper to bumper traffic it would become so painful to drive that I would not enjoy it. As wive's usually are, I decided she was right. I sold the 2F drivetrain for enough to cover the cost of a Gen 3 5.3 LS + automatic overdrive transmission + a custom made wire harness and ECU flash. I then called to purchase the Advanced Adapters parts I needed to connect the automatic overdrive transmission to my Toyota transfer case. Much to my surprise, they told me if I insisted on it they would sell it to me, but that when I got it up to speed the transfer case would whine so bad and so loud that it would drive me nuts and not be at all enjoyable. But, they told me that if I installed a split transfer case from an FJ60 it holds more gear oil and does not have the whine problem. And buy the crossmember for the FJ60 and cut the ends down to fit. So I bought the Advanced Adapter for the split transfer case, and found that cruisermatt had several good used split cases and I bought one from him. Oh, and I don't know if your '72 is the same as my '71 but my control knob to put the transfer case in 4wd high or 4wd low is mounted to the bottom of the dash from the factory instead of on the floor, and through some linkages it operates a vacuum switch to switch the transfer case. So, cruisermatt sold me a split transfer case that is vacuum actuated so I can use my factory knob on the dash to shift the transfer case, which will by far be easier for me to do instead of leaning and bending over to the floor to shift a short stick.
Also, if you decide to do an LS swap and EPS (Electric Power Steering) like I did, then you will want to delete the power steering pump on your LS or LM7 (truck & Tahoe cast iron block version of the LS) engine. I did some searching and called a company named ICT Billet. They make brackets for anything you can imagine. Below is a link to the correct part number needed to delete the power steering pump and adds a bracket and idler pulley in place of the power steering pump to get more belt wrap around the water pump rather than just removing the power steering pump and putting on a shorter belt (which does not give you as much belt wrap around the water pump and can make the belt slip and can cause your engine to get hot), for a Gen 3 LS (or LM7) found in a Tahoe, Silverado, and so on:
LS Truck OEM Location Alternator Bracket - PS Delete - LS Truck OEM Location Alternator Bracket - PS Delete - https://www.ictbillet.com/products/ls-truck-oem-location-alternator-bracket-ps-delete?variant=47267501703398
AND, they no longer make the bracket & idler pulley that allowed you to use the original factory serpentine belt, so the belt number that you will need is: k060755
If you get a different LS than a Gen 3 and want to go with electric power steering and delete the power steering pump I would call ICT Billet and they will let you know which bracket & idler pulley you need.
Hope that all helps you or someone else reading.
Oh, 1 other thing, in the thread Best FJ40 Upgrade Ever I noticed that many people said power steering. But, adding traditional power steering was going to be expensive and involve swapping out a bunch of stuff. But then someone posted in that thread about Electric Power Steering (like all modern cars have) and that it was a fraction of the cost of regular power steering. If interested, here is where you can get that setup for a fraction of the cost of other EPS kits out there, and it is adjustable so you can set the amount of steering assist to the way you like it:
Straight Electric Power Steering Kit - ePowerSteering - https://epowersteering.com/purchase/product/straight-kit/?v=84de8e2b14bb
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I've done a swap or three, used NV4500 along with Toyota 5 speed. Hands down the Tremec 5 speed behind a 6.0L was my very favorite.
- Thread starter
- #14
Thanks for all the info!
FloridaLife
SILVER Star
I couldn't afford the 6.0 or 6.2. It sure would have been nice though! I had to go with the 5.3. I guess I should have sold my 2F drivetrain for more money so I could have done the 6.0 or 6.2.
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5.3 is enough power to drive a 40 as fast as you want to go, do burnouts, donuts, etc
If it is wet out you will be able to spin the rear tires at speed. You will have more then enough power
I agree. The 5.3 will push your 40 around with ease. I was commenting on the trans more than the engine.
Stock Lm7 5.3
Stock fj40 4 speed
Stock fj60 split case
4.10s
33s
I don't think I would ever run that fast again though.
I had just buttoned up my swap and reinstalled my roll cage and wanted to see what this thing can do.
Went out with ear plugs in, the GPS was sitting in a cup holder, went out on a *closed course* near the house and kept in it, the speedo indicated 100 which was fun, but when I got back to the house the GPS had this reading, I was disappointed I didn't get triple digits.
I don't think I'll be running it that fast again though, I was over taken with excitement at the time for how good it drove.
Not exactly sure what my RPMs were as I couldn't hear the engine over the wind noise and the ear plugs. Probably too high, But the drive line had more in it, I ran out of testicular fortitude.
Stock fj40 4 speed
Stock fj60 split case
4.10s
33s
I don't think I would ever run that fast again though.
I had just buttoned up my swap and reinstalled my roll cage and wanted to see what this thing can do.
Went out with ear plugs in, the GPS was sitting in a cup holder, went out on a *closed course* near the house and kept in it, the speedo indicated 100 which was fun, but when I got back to the house the GPS had this reading, I was disappointed I didn't get triple digits.
I don't think I'll be running it that fast again though, I was over taken with excitement at the time for how good it drove.
Not exactly sure what my RPMs were as I couldn't hear the engine over the wind noise and the ear plugs. Probably too high, But the drive line had more in it, I ran out of testicular fortitude.
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FloridaLife
SILVER Star
That's pretty awesome for an fj40!
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My FJ62 has been ~125mph in trip trim (~6000lbs) with a stock 5.3 and that was before I boosted it