Some advice on my CJ6 project please

[BDASH]

G'day everyone, well I have recently joined the ranks of "real" Jeep owners by purcahsing a 1975 CJ6.

AQ few mates and I are planning it as a project, not to make it show room, to be practical (and a bit of fun ;-))

We are doing the driveline analysis at the moment.

It currently has:
- an AMC 232 i6 that is going, but should be rebuilt
- a Spicer T-14 3 speed
- a Dana20 t/case with a fairly average low range ratio

We are toying with the idea of ripping out and replacing all three...this is where I'm after some advice if possible.

We have access to a recently reco'd Holden 253 and a rebuilt M20/21 gearbox for a nice(ish) price and also have access to a 283 Chev (that needs to be rebuilt). We are also looking at some Toyota 5-speed gearboxes.

If we went with either of these motors, are theses the right gearboxes? Should we be looking at autos? If so what? and of course, any ideas on transfer case?

We haven't worked out a decent budget yet, but "not much" is the answer.

Any thoughts/suggestions would be appreciated. Thanks.

[Moses]

if you do go with a Toyota 5 speed box make sure you get a Supra 5 speed they are a bloody strong unit

also they are easy to find an adapter to bolt to any Holden or Chev

[AussieCJ7]

Options are just about anything you can imagine

1. 4.0L I6 and aw4 4 speed auto out of a XJ/TJ around 5 to 6K
2. holden 308 and turbo 400
3. ford 302 and C4
4. chev 350 and turbo 400


If you want a manual then things get a little more complex as to find a manual that will stand up to the abuse for a reasonble cost but check out

http://www.novak-adapt.com/catalog/trans_to_transfer_adapters.htm

I would let the engine you pick decide yur tranny as it is easier to avoid adapters that will make it harder and more costly

Transfer case the options that jump out is D300 but once again decide on engine and tranny then see if an obvious choice jumps out

have you considered diesel ? this can open up some cool options also

[Glenn]

I have the original 232 3 speed box and transfercase in my Jeep, I love them they are strong and relatively cheap to run and repair, I'm at the moment in the process of putting lower gearing in my dana 20 as that is a little lame as far as low range goes.
One great swap would be finding engine and transmission from a wrecked XJ, would have more go than the holden or even the 283 chev, I've seen XJ's on the road for sale for under 5 grand so you should pick up the drive line for less than than that.

[BDASH]

if you do go with a Toyota 5 speed box make sure you get a Supra 5 speed they are a bloody strong unit

Thanks Moses, with a 3.95:1 first gear, I already had the W59 Supra Oval box at the top of my list, but price might become an issue...stay tuned.

[Wooders]

Just personally I consider the Holden 253 as a dog that fleas reject.
If you are doing it to keep it Jeep then IMHO either swap in an AMC 360 (with TF727) or EFI4.0 (with AW4 auto).
The dana20 isn't as strong as the D300 - but it's still a good box. Get some better ratios for it & you're set.
Depending on tyre size, the next weakest link will be your axles.

[BDASH]

...Transfer case the options that jump out is D300...Thanks Aussie, I'll look into this further, I think this replaced the D20 for CJs from 76...right?

...have you considered diesel?
...hmmm, a mate mentioned this but I hadn't really started looking at it as a viable option because I have no experience with diesel engines and I just automatically thought of petrol.

Can you or anyone tell me of anything to think about re: older diesel engines. I know that the new CRDs in the Jeeps rock, but isn't that because of new technology?

One thing that I realised that I didn't mention, is that we are thinking about building this Jeep to go in a charity bash (Variety Club or the like) which means that the engine we put in need to be no larger capacity or no newer than the CJ6...which means that the engine must be no greater capacity than the AMC304, or newer than 1975 (in fact probably 1974 because that is what's actually stamped on the plate from the factory).

[BDASH]

I have the original 232 3 speed box and transfercase in my Jeep, I love them they are strong and relatively cheap to run and repair, I'm at the moment in the process of putting lower gearing in my dana 20...
Thanks Glenn, what ratios are you putting in the Dana20? If that is a viable option then maybe the engine and gearbox are all I need to look at.

With regard to the engine, it needs rebuilding (which is why I'm looking at options:-)) but you mention "relatively cheap to run and repair". Although I haven't exhausted all my possibilities yet, I'm yet to find a complete rebuild kit for the 232. Any ideas?

[murray]

have been down this track before
sm block chev t400 jeep factoy adapter to dana20 trans case
had this setup in a cj6 for years
by the way i have t18 gearbox and dana 20 for sale pm me

[BDASH]

Just personally I consider the Holden 253 as a dog that fleas reject. :D


If you are doing it to keep it Jeep then IMHO either swap in an AMC 360 (with TF727) or EFI4.0 (with AW4 auto).Keeping it Jeep wasn't high on the list for the driveline if that added extra cost, however as I just wrote in one of my reply posts, we are looking at doing a charity bash, which in this Jeep will limit us to a pre-1975 motor and no larger than 304ci (unless of course someone can point me to a site saying that a CJ6 had a 360 before 1975 ??)

[BDASH]

The dana20 isn't as strong as the D300 - but it's still a good box. Get some better ratios for it & you're set. Do you have any? What ratio? How much? (PM if you prefer)


Depending on tyre size, the next weakest link will be your axles.
We had planned on 32's for now, but gearing up to go bigger later (35's ??) It currently has the standard track CJ axles and a disc conversion on the front. When we pull out the axles, is there anything that mightn't be obvious to look for?

[BDASH]

have been down this track before
sm block chev t400 jeep factoy adapter to dana20 trans case
Thanks Murray

[AussieCJ7]

:D

Keeping it Jeep wasn't high on the list for the driveline if that added extra cost, however as I just wrote in one of my reply posts, we are looking at doing a charity bash, which in this Jeep will limit us to a pre-1975 motor and no larger than 304ci (unless of course someone can point me to a site saying that a CJ6 had a 360 before 1975 ??)


well that changes the ball game BTW not sure how the rukes are wriiten but no Australian deilvered jeeps got the 304 so you may have to stick to 258 ?? Not sure the CJ6 ever got a V8 I think it was only the CJ5 & 7


does that mean your also stuck to jeep engines ???

If you are stuck to jeep engines then build a 258 with a 4.0L head and mpi no one will know it is any different than a 232

If you not stuck to jeep engines then look your really limited to a ford 302 if you want a decent v8 pre 75 and no more than 304ci or a amc 304 but good luck finding one in aus

[Glenn]

Murry's T18 4speed gear box might be the go, they usually have the ultra low first gear, something like 6 to 1, which would cure your low range problem.
As for rebuilding your 232, when I stripped mine down I discovered it only needed rings and bearings and a rebuilt head, not bad for something 30 years old, all parts were pretty similar in price to anything else I had worked with, dearer than say old ford or holden but not outlandish. The best thing I did to that 232 was put in electronic ignition and distributor from later model cj7 as well as the inlet manifold so I could run a 350 holley, the little bugger dosen't miss a beat now,
Oh and I'm putting dana18 gears into my dana20, will give me 2.47 low range instead of 2.01, I had to source a bronco upper sliding gear from the states which cost me 200.00 to complete the mod, I had the spare dana18 sitting around. Trouble is now I've discovered the T14 gearbox has a ten spline output rather than six like most Jeeps, so I can't use the dana18 input gear:-(
not sure what I am going to do there yet, where there is a will there is a way

[BDASH]

...If you are stuck to jeep engines then build a 258 with a 4.0L head and mpi no one will know it is any different than a 232

If you not stuck to jeep engines then look your really limited to a ford 302 if you want a decent v8 pre 75 and no more than 304ci or a amc 304 but good luck finding one in aus
Thanks again.

Because the CJ came out of Toledo, I'm sure I could find enough stuff to say that a 304 was an option. A couple of the guys say that I'm trying to read a loophole into the rules about it re: year and size (they say that it really means, only what was available in the model)...but we are waiting on actual clarification.

I like the idea of the 4.0L head on the 258, although if I was going to go with a 258, I might as well stickwith the 232 (for now) and play with that.

My cousin actually suggsted a Windsor or Cleveland 351 or 302 before I mentioned anythig about the rules...that is definitely on the list of options.

[BDASH]

Murry's T18 4speed gear box might be the go, they usually have the ultra low first gear, something like 6 to 1, which would cure your low range problem.The T18A seems to have been the box with the 6:1 first, but the T18 seems to still have a respectable 4:1 first. But a couple of posts have got me thinking again about a Turbo400 Auto...hmmm....


As for rebuilding your 232, when I stripped mine down I discovered it only needed rings and bearings and a rebuilt head, not bad for something 30 years old, all parts were pretty similar in price to anything else I had worked with, dearer than say old ford or holden but not outlandish. The best thing I did to that 232 was put in electronic ignition and distributor from later model cj7 as well as the inlet manifold so I could run a 350 holley, the little bugger dosen't miss a beat now,Good ideas. Before we seriously look at any other engine, I think that we'll rip the 232 out, strip it down and see what we've got to play with. Thanks.


...I'm putting dana18 gears into my dana20, will give me 2.47 low range instead of 2.01...I've read about this conversion on an article on www.off-road.com. Is this the best/only option for ratio changes with this transfer case?

[wee doggie]

First work out what year motor you can get away with then it's simple. If age isn't an issue go for a Holden V6 with 4speed auto. You get a low 1st gear to help compensate for your 2:1 low range plus an overdrive so you can stick with your 4.27 diff ratio and 32s. The length of the auto isn't a prob in a CJ6. The V6 is 3.8 litres the same as your 232. If you have to stick with a 74 model I'm sure you could find an old Buick 3.8 about that vintage if you look hard enough and then mate it up to the T700. Too easy excepy for doing it on the cheap and if that is your priority don't change anything just drive the thing.

[AJ CJ5]

if it were me, and im actually doing this to my CJ5.
I would do up an old 302 windsor, with the heads done for diet petrol. with a good towing cam and intake manifold only.
Put that power through a T18a with the "granny 1st gear" then to your Dana 20 then to your rear diff and if you have the change left over, throw in a detroit locker in the rear at least.

The only piece im missing is the D20. Im in the market for one shortly fellas.

[BDASH]

...I would do up an old 302 windsor, with the heads done for diet petrol. with a good towing cam and intake manifold only...Thanks AJ, this is now definitely on the optional setup list. Cheers, Brett...