Gears

[Clifton]

I appreciate all the input on the previous thread about the big block in the jeep. I think I will just stick with 4.2 for right now. I will probably put some 1:7 roller rocker on it and get just a couple more horse power out of it. The engine is not that old so I really dont want to go into the bottom end yet to get more horsepower out of it. I am gonna look an gearing it and cant make up my mind. The jeep has the stock gears in it which beleive are 308 or taller. It also has 33x12.50 Mickey's on it, they are mtz's which are a great tire so far. I cold possibly go with a taller tire such as a 35 in the future as the jeep will be getting a spring over axle kit. I was looking at going with 373's, I was told with that tall of a tire it might still be a little tall geared. My choice is between a 373 or 410. Now I will have changed the tranny to the SM465 gm tranny by this time as well which shouldnt make a difference in forth, I am pretty sure it is a 1 to 1 final ratio in forth like my t-4 tranny is right now. I just want a stronger transmission. My major problem is i will still be driving this thing on the street and probably on a couple of long trips a few times a year so I would like to get some time of fuel mileage out of it. Right now it is so under geared in 4th it is being lugged everywhere you go. With all the modifications on the engine it still pulls a trailer well but is just kinda hard on it, but it really doesnt get that good of fuel mileage. Now I am a realist and dont expect to get some kinda super saver either way, just want to find the happy medium is all. I would like to get 12 to 14 mpg out of it and still have the power to pass a slow mover going down the road. Oh, has anyone tried the OX lockers in there differential. Kinda interested in them. Any feed back would be appreciated guys.

[Clifton]

My typing

Sorry about the mispelled words on the post, sometimes my fingers out run my brain.

[ECV Jeep]

If you are keeping the 4.2 block may I suggest the MPI kit and a 4.0 litre head. I did this conversion to my Jeep with headers and the thing pulls pretty strong. Check out this link...

http://www.geocities.com/035jeep/40L.html

and check with HESCO for the MPI kit.

I am running 4.88 gears with a detroit and ARB, so I cannot be much help on the OX locker, except to say that those who I know that run them like them.

[Clifton]

I have a 4.0 HO head on it now, with a howell fuel injection TBI on it and HEI destributor from performance distributor, and offenhauser intake and an electric fan instead of a manual one. It runs pretty good. I went with the TBI from chevy because I know it better and it is super super simple.

[Jerry Bransford]

What is the final gear ratio for that SM465? Does that tranny have an overdrive? Yes I'm too lazy to look it up right now, I'm plumb wore out from cleaning and working on the frigging bbq for friends coming over later today to use my brain for anything right now.

[aw12345]

sm 465 is a 4 speed 1st is a deep granny gear
4th is 1:1 for highway driving 4.10 or 4.30 gears if you can find those. 4.30 should work sweet

[headhunter]

sm 465 is a 4 speed 1st is a deep granny gear
4th is 1:1 for highway driving 4.10 or 4.30 gears if you can find those. 4.30 should work sweet

The granny gear on the SM465 is 6.55:1. I'm thinking that this will keep from having to go as low as 4.56 or 4.88, so it should retain some mileage on the highway with 4.10 in the diffs and still be good off road.

That's all theory on my part, so listen to someone that has actual experience with this tranny. I'm thinking of doing the same thing with the SM420.

Christian

[Ol Man]

My CJ7 with a T-19 has 6.32 gears and the diffs are 4.10 and it is pretty good for a freeway driver with 35s. I would recommend the 4.10s for the diffs if you go with the 455. If you are serious about rockcrawling, I would recommend lower transfer case gears also. You might also consider an automatic. It would be nice off-road, nice around town and good on the freeway. Just a thought.

[Linus]

Hi, I'm running the OX in the front end of my CJ7, no complaints at all, traction on demand without having to worry about air or electricity. The big consideration is where to put the shifter. The instal instructions were pretty simple and easy to follow. I regeared at the same time, went from 3.31 to 3.73. I spend a lot of time on the highway, and wanted to run 33" tires and keep the final drive ratio as close to stock. Ended up with 32" tires and am still wishing I went with the 4.10. Just doesn't go slow enough on the trail.

[Guest]

I have the 4:10 now and no regrets! I have 33" tires. I have a good top speed. PM me formy top speed. It's up there. No worries on the freeway.

[OU812]

You know its fast if he wont post it.:gun: