Hi, I am looking to swap a 72' 350 into my 68' fj-40. Other then the transmission, and anything in the engine bay, what do I need to consider switching, or modifying? (axles, gearing, etc.)
Engine Swap on stock axles (1 Viewer)
- Thread starter Joes68fj40
- Start date
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Welcome to Mud!
Your question has a thousand answers. It all depends on what you plan to do with the vehicle.
The FAQs are a good place to start.
forum.ih8mud.com
Your question has a thousand answers. It all depends on what you plan to do with the vehicle.
The FAQs are a good place to start.
FAQ - 40-series FAQ
Welcome the the frequently asked questions about the Fj40 and Fj45. As Fj55's share a fair amount of components, there may be some links to posts involving 55 series. The FAQ will be locked, but the topics that are linked to will still be open, so if new info comes up, or someone has a...
forum.ih8mud.com
jim land
SILVER Star
Do you plan a h42 4 speed
Welcome to the forum! Your question is a common one and this forum with sure give you lots to consider regarding the swap. As @pjohnson stated above, your intended use as well as other changes like tire size will have a lot to do with it. Oh, and by the way..........post some pictures or your 40 doesn't exist
- Thread starter
- #5
I joined today, thats why theres no pictures lol. but anyways, I am in highschool, and I just finished restoring my 40, I daily drive it, but no where far, just too and from work, and school, so i will not be doing any crazy rock crawling, just yet because it still has the original suspension that is a bit too rough to take off roading, because of this i plan on eventually swapping the suspension to either bilstein or OME. Then because my 1F isnt all that reliable, I plan 350 swapping the 1F, and eventually swap some old toyota taco or 4 runner axels with disc brakes into the car. how crucial do you think the axle swap would be for just a casual daily driver.Welcome to the forum! Your question is a common one and this forum with sure give you lots to consider regarding the swap. As @pjohnson stated above, your intended use as well as other changes like tire size will have a lot to do with it. Oh, and by the way..........post some pictures or your 40 doesn't exist
Glad to hear you have a plan. My very 1st cruiser back in the late 80's was a rust free 67 FJ40 from El Cajon, CA (bought it for $100
). It was all stock with the 3-speed on the floor, stock axles, and stock engine (not running). I knew nothing about cruisers but I had a nice rebuilt 350 sitting around that needed a home so I swapped out the 1F engine and replaced it with the V8. I bought my engine adapter from Downey Offroad (Downey is gone, but Jim isn't @Downey ). The adapter from the V8 to the stock 3-speed installed perfect and worked flawlessly. I also installed a 4" lift from Downey Offroad as well with 35 x 15.5 x 15" (OG) Super Swampers. I put that rig through offroad hell & back with the stock axles, transmission, & transfer case. This was not rock crawling but mostly mud and hills which is really all that Wisconsin had to offer at the time. Had that rig for a couple years using it as a daily driver and weekend mudder. Never broke a single thing but I had a hell of a time keeping it from overheating in the summer. I know now that the over heating was my fault for not having a proper shroud/fan setup. Sorry for the long story but I love talking about the early days of my cruiser discovery. I say do the swap if you want and the rest will hold up fine as long as you are not trying to drag race on the pavement. Have fun, enjoy the journey, and learn as much as possible along the way. You already made the right move by joining this forum!
- Thread starter
- #8
my tires are 33sDepends upon use and paranoia
My old FJ40 went with 5.0L TBI engine with SM465 and stock one piece case. I kept the stock axles with 4.1 gears and 35" tires. Never broke anything but I'm a technical wheeler/rock crawler.
All three of my FJ55s are doing Dana 60 axles with 35 spline through out. One is 6.0L with NV4500, split case, 4.56 gears for 35" tires. One is turbo 5.3L with 4l80, a doubler with split case, 5.38 gears for 43" tires. Last is 472 Cadillac big block with sm465 with split case, 3.54 gears for 35" tires.
My resurrected FJ40 will be going Dana 60 axles also.
As I got old, I have gotten paranoid. I don't trust the one piece case to any amount of power. My transfer case guy tells me a split case will easily handle a turbo'd 5.3L engine and a 472 big block cady. An adapter is an adapter.
The axles I just don't trust period. Can they be built up? Sure, they can sniff stock Dana 60 strength at the cost of a stock Dana 60. The slight loss of diff clearance is a non-issue for me. I've never had issue hitting them.
also the tires are 33sWelcome to the forum! Your question is a common one and this forum with sure give you lots to consider regarding the swap. As @pjohnson stated above, your intended use as well as other changes like tire size will have a lot to do with it. Oh, and by the way..........post some pictures or your 40 doesn't exist
- Thread starter
- #9
i realize that, it is slow, and its not quite as much the engine as it is random issues such as the starter, and my engine being too cold to wanna start, and various small problems that occur quite oftenYour F engine can be very reliable. Its just not going to be fast
Start with safety upgrades like front disc brakes. Drive it, enjoy it and LEARN about it. Your plan will evolve from there.
- Thread starter
- #10
im not sure yet, i do know the transmission is a turbo transmission, similar to the ones the old firebirds had
If it's a TH350 (Turbo 350) then it's not the stock tranny. Grab a couple cell phone pics or something and upload them.
reddingcruiser
Practicing for retirement
I say quit while your bank account is still intact or you'll be like the rest of us - trying to stay ahead of the last upgrade and chasing the next weak link 
A starter, or any other accessory, can fail on any older engine. That's just normal aging and maintenance. If you use the collective wisdom here in the forum and get your F engine dialed in, it'll last a very long time and you'll learn a lot.
I have lost count of how many new 40 owners jump into a major upgrade project without enough knowledge of the vehicle and then abandon the project due to frustration or lack of $$. On top of that, they never got the chance to really enjoy their truck before they tore it apart.
Full disclosure - that was me with my first FJ40.
pb4ugo
SILVER Star
Swapping out stk 40 axles and installing taco or 4 runner axles is a step backwards strength wise. It's better to just swap out the knuckles and disc brakes only and adapt them to the 40 axle. I'm with pjohnson, please explain the turbo 350 trans comment. The stk 4 speed can handle a 350sbc. The stk t/case is questionable but will be OK for moderate wheeling.
Downey
SILVER Star
As far as I know I'm the only guy who ever built an adapter to run a GM automatic transmission behind a stock Landcruiser 6 cylinder engine, and I believe that one-and-only adapter ended up in a Landcruiser museum??? An Inline 6 with GM auto trans in an FJ40 would end up with practically zero rear drive shaft???
I'm not in love with the Landcruiser 3 speed trans, but I have to admit that back in the day I towed a fully self contained travel trailer to every monthly wheeling run in mountains/desert with a 300 h.p. 327 with 3 speed trans, with 33's for many years with zero problems.
If you did choose a V8 with 3 speed tranny, I not only have the adapters and motor mounts you will need, but I have a freebie 3 speed tranny you can have (you pay postage). If you jump onto the Downey Off Road link here on Mud you can print out a copy of the Downey V8 installation instruction manual.
I'm not in love with the Landcruiser 3 speed trans, but I have to admit that back in the day I towed a fully self contained travel trailer to every monthly wheeling run in mountains/desert with a 300 h.p. 327 with 3 speed trans, with 33's for many years with zero problems.
If you did choose a V8 with 3 speed tranny, I not only have the adapters and motor mounts you will need, but I have a freebie 3 speed tranny you can have (you pay postage). If you jump onto the Downey Off Road link here on Mud you can print out a copy of the Downey V8 installation instruction manual.
I think the OP is referring to the trans behind the 350.
- Thread starter
- #17
I currently have the stock 1f and stock transmission, the turbo transmission is the one id put in with the 350As @pjohnson says, learn your rig... fix what fails or prevents you from your style of driving/wheeling.
I daily drove my first FJ40 (75) almost complete stock for 3 years. The only upgrade was 'mini truck' front disc brake conversion. After that, it was upgrades based upon rock crawling(5.0L TBI swap with SM465 tranny and spring over for 35" tires)
My first FJ55 was a continuation of that learning process as is my resurrection of the 75 FJ40. My other two FJ55s are one upping myself toys
For 33s, I wouldn't sweat the axles unless you are overly aggressive when wheeling.
It is odd you are saying 1F but auto(Turbo 350) at the same time. That almost sounds like you might have a Chevy I6 swapped in.
- Thread starter
- #18
thats correct, the turbo trans is the one with the 350
- Thread starter
- #19
I believe my dads trying to stay away from another 3 speed, i believe he wants a 4 speed or so, also i meant that the turbo transmission was the one that went with the 350, my current is the stock 1f 3 speed transmission
- Thread starter
- #20
i meant that the turbo transmission goes with the 350 engine, i currently have all stock 1f with the matching 3 speed transmission.
