Stock 1964 Cj5. What To Do

The issue isn't so much power or gearing. The real issue is you have a tall, narrow rig with arcane suspension, mediocre brakes, sloppy steering, lap belts (maybe), simple roll bar (maybe) and nonexistent safety features. Tire loss, collision, or ANY emergency maneuver at speed can be a crap shoot at best.

 

If you want to travel in the 60-65 mph range in a Jeep (without a lot of upgrades), you need to start with a ‘66-up with a V6, or better yet, a ‘72-up that has many improvements. The F134 is not really up to the task. With 4.27 axles, you can touch 70 mph downhill or with a strong tailwind, but its really taxing on the engine. Your Jeep likely has 5.38 gears, so you can expect to touch 60 mph. These are short wheelbase and high center-of-gravity vehicles that weren’t designed for higher speed travel.
In stock form, your Jeep is more comfortable in the 45-50 mph range, as it was designed for. Enjoy it for what it is.
-Donny

 

… with the wind.

 

Can it be any worse than a Suzuki Samurai? I get where you're coming from. I'll be doing 3 point harnesses and maybe high back seats (save low backs for shows). Sounds like brakes and steering ans suspension bushings will bey 1st set of go tos. I'm a believer in hp last.

And yeah, intake valves only in the head is wierd. I've worked on old flathead Kohler engines in john deeres but never something like this. Even the British A series, based on a 30s tractor, was full overhead valve. Not a cross flow design though.

 

The Samurai might have more top speed than the F134. Power is torque times RPM, and the very long stroke of the F134 limits both revs (rod velocity gets very high) and makes the torque peak early. Feels strong at low speed, but poops out at highway speed. And the gear ratios already take nearly as much advantage of the engine as possible. Taller gears means the engine has less power as the air-resistance-barrier is reached, and the Jeep has very poor aerodynamics. Drag goes like the square of velocity.

 

I was in the Civil Air Partol as a kid and these willys were our vehicle of choice. I had the joy of almost bouncing out at highway speeds from the back seat on several occasions. Living in Maryland, most of the back roads are speeds limited to 40 or 50 but you invariably have to hop on a highway to get from a to b so I'm just thinking about those brief moments. I like the overdrive option.

 

Welcome from Michigan, I put 66 V6 axels in my Jeep with a F 134 it now has 3:73 gears and 10" brakes and it will go 60mph, but that is pedal to the metal, which I don't like to do to my new motor. I gave my 4:27 axels to my friend and they are available if you want to go that way. They still have 9" brakes though. If you can find a Ross steering box from a V 6 they are better than the stock Ross in 64. Then replace the ends on your tie rods and drag link to make it safe, I also put a steering damper on the tie rods, stops the Willys Wobble. The guys on this site are Great People and have helped me make any discission's on what I need to do. I wanted to keep my Jeep as stock as possible, but still Safe. Good Luck Mark. Rick

 

While comparable HP wise, the Sammy is lighter, smaller (slightly) and has modern steering and brakes. It will do highway speeds, but I'm not enthusiastic about an emergency maneuver in one either (my son in law has an 86), but would take the collapsing steering column and knee bolsters over the spear sticking up at my chest in my 71.