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C

Cryals

Joined
Jun 3, 2026
Threads
2
Messages
8
Location
nevada
I need honest opinions!!

I have a 78 fj40 and it has the 2f with stock 4spd trans. My goal is to get it to drive somewhat “modern” like be able to cruise at 60mph+ and not have the engine scream at me.

I have debated doing a 5.3ls swap with stock 4spd trans

I have debated h55f for overdrive (still stock engine doesn’t give the output)

This vehicle will be used as a cruiser and would like the option to be able to drive it across state going faster than 45-50mph and to be able to go up grades without getting tired. Would also like to be able to go out in the mountains with it.

Seems like everything I want out of it comes from V8 power but also Chevy doesn’t have to be the answer, it’s just the cheapest and most readily available parts. I would also like to be able to get better fuel economy.

I’d love expert advice here
 
I think an overdrive is the ticket NV4500 comes to mind. I was going to do a hand built 283 corvette engine (flat tappets, big valves, better cam...) Not an aluminum head/block person or fuel injection. I don't mind adjusting points, valves, carbs.

You should read the tons of build threads to see what people have done to their rigs.
I think it would be cheaper to get the FJ Cruiser with a 6 speed manual
 
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5.3 with an overdrive is the way to go if that’s what you’re looking for. It will still scream at you but at least you can scream back.
There are plenty of threads on here with the LS series plus 5 speeds or the 4L60e. I run at about 2000 rpm at 65-70 with 33’s. Gas mileage has improved to 16 to 18 mpg at highway speeds. I’m running a 5.3 LM7 plus 4L60e.
With the stock 2F and 4 speed you could bump up to a taller tire and rubber overdrive it. I ran an F.5 and 4 speed for years with 33’s and it drove pretty good. Until I seized it up. That’s the only reason I went with the newer combination. The V8s are a hoot to drive but you lose a bit of the FJ40’s soul.
 
I have not driven a healthy 2F. Mine was real tired when I got my 40. I think they have enough power to make them driveable when they aren't worn out or sickly.

With that said, I have a 4 cylinder diesel swapped in. There are things I love about it, there are things I hate about it. I wouldn't do the R2.8 if I were to do it again. It's not that it's bad, it just isn't great. My complaints are vibration, power delivery/tuning (gearing helped a ton offroad for power delivery complaints), and on the real minor side of complaints a little more power would be nice. It's a 116hp at the wheels when I had it dyno'd for funsies. It's functionally adequate.

I do have a H55 and a split case transfer case. The overdrive in that transmission at 60mph gets me almost a 400 rpm drop. Which is nice, especially with the diesel. I also have 3.70 gears. I'm at 2100rpm at 60mph.

I can run down the four lane roads at 72mph quite comfortably. It'll go faster, it just seems to be a sweet spot for everything around that speed.




If I were to do it again.... (which I might if the Chi-Cummins decides to grenade)
Full disclaimer, I am a inline six fanboy. And a big fan of diesel when they are correct. I'd do a Mercedes OM606 for a diesel.

If wanting to stick with gas. I really like the Toyota 1FZ. Peel back the retarded Toyota engine management, better head studs, and it'll go eternally with adequate power. I wouldn't rule out a 2F either. Some work on that, and you aren't going to have a power monster, but that engine does have it's appealing quirks. Also the 2F is pretty much the simplest solution. Yack one out, stuff the other back in.

I'm not a fan of V8's in general, but a GM swap is the easy button for power and ease of sourcing things. There's plenty of really good V8 engines out there.
I had an S10 with a 4.3 V6, I really liked that engine, and I'm surprised that swap doesn't happen more often. All the same adapters to driveline as a GM smallblock. (it's just a 350 with 2 cylinders lopped off) It would package up nicely in a FJ40 too.


Just my opinions. Everything has it's pro's and con's. I do like the newer transmission and transfercase. I think that adds a fair amount of drivability.
 
X2 on the tires and gears... I'm old school and have really liked the 3FE's in 40's that I have driven. Quite a bit more pull than healthy 2F's and plenty of the low end torque needed off-road Its not a highly difficult swap since it's a later F block. Yeah its old an heavy but IHO adequate power and highly dependable.

That said, I can comfortably drive my tired 2F (as comfortable as a 40 can be) at 65mph all day with its 4.11 gears and 33's on flatter ground, long grades are a different issue though ...
 
sogncab said:
I'm not a fan of V8's in general, but a GM swap is the easy button for power and ease of sourcing things. There's plenty of really good V8 engines out there.
I had an S10 with a 4.3 V6, I really liked that engine, and I'm surprised that swap doesn't happen more often. All the same adapters to driveline as a GM smallblock. (it's just a 350 with 2 cylinders lopped off) It would package up nicely in a FJ40 too.
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That is a good point, however I think most simply decide for the exact same work, systems and cost and even GREATER availability it is more reasonable to just get all 8 cylinders. The V8 is already 2/3 the number of longitudinal cylinders, and significantly lighter than the old 6. But you are not wrong in many cases it would be great/fine.

Some of us have a separate individual bias as well; being in Colorado we can regularly and easily go to 10,000 ft - 11,000 ft elevation.. that is a 33%+ loss in horsepower and torque.. so the “spare” 2 cylinders are kind nice… basically your V-6 at altitude… (or in your case.. a 4 cylinder!)
 
What exactly does number of cylinders have to do with anything power related?

I like inline sixes because they are naturally balanced and generally take abuse well.

Elevation calls for a safety turbo. 🤣
 
77mustard40 said:
X2 on the tires and gears... I'm old school and have really liked the 3FE's in 40's that I have driven. Quite a bit more pull than healthy 2F's and plenty of the low end torque needed off-road Its not a highly difficult swap since it's a later F block. Yeah its old an heavy but IHO adequate power and highly dependable.

That said, I can comfortably drive my tired 2F (as comfortable as a 40 can be) at 65mph all day with its 4.11 gears and 33's on flatter ground, long grades are a different issue though ...
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I have 33s and 4.11 gears. If I hit 65 I’d probably be screaming in that thing
 
Cryals said:
I have 33s and 4.11 gears. If I hit 65 I’d probably be screaming in that thing
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You get used to it (and 65 is 65 on the GPS, not the speedo)
 
brian said:
33's with 3:70 rears.
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This.

I'm running this setup on my ('79 build) 40, and it cruises all day long at 65 mph, at about 2,450 rpm.
 
Nope, it’s a semi worn out original 2F with a stock carb, clean and well functioning cooling system and a later model electronic dizzy recurved for my desmogged tractor motor.
 
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You can cruise around 85mph all day long in foam seat comfort

 
@brian

7 … but in comfort … so I’m guessing Japanese men and not Dan Haggerty types :meh:

:)
 
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