5 SPEED TRANSMISSION CONVERSION ON A 1977 FJ40

[Hoosier 45]

It is funny to think, back in about 1988, a buddy and I drove my 1977 fj40 from Indiana to LA via the grand Canyon and back in 10 Days we only passed 2 vehicle on the WHOLE 5000 mile trip, to get the best mpg we could, we drove looong streaches at 45 -50.

About 4 years later my new wife and I drove the same beast to Idaho and back on our honey moon. Looking back I guess it was kinda nuts. ah but those were the days! I still have the wife and many parts of the 40 are now transplants in the 1965 fj45 pick-up.

[Jonathan Hanson]

I'm now considering 35" tires. Can anyone show me the calculations to figure out engine rpms and cruising speed based on gearing and tire size? Our trans and axle gears (4.11.1?) are stock. I'm not sure how 35's would look on a stock rig though.

Rather than worrying about how 35s would look, I would be concerned about how they would perform. You'd almost certainly run into clearance issues without more lift and/or fender trimming. More importantly, 35s are on the edge for the stock birfields. If you go from 4.11 diffs to 3.70s, you gain drivetrain strength. Installing ever-larger tires loses drivetrain strength.

[JohnnyS]

H41, 3.70s, and keep your 33s....
None of my 40s have ever been fun at over 65.
I maxed my 76 FJ40 out down some big hills (Black Canyon on I-17 being one) and it was freaking scary; I was much younger and dumber.