Theoretical Cj6 Build Ideas

I can talk for hours about the 4.3 but the "easiest" in a CJ5 would be a early 90s tbi non balance shaft motor.

Because you can use short water pump accessories and small cap distributor.
This is a tall motor with intake and filter so it doesn't work in a low hood but it is a "unit" that only needs electrical, fuel (14psi), and coolant.
This one has the same front and rear profile as a sbc v8 and shares a lot of parts making them cheap.

Earlier carburetor engines do not have roller lifters or small distributors.
Later motors with the balance shaft finish longer overall and have more V6 specific stuff, you have to sort out the intake and filter, the aluminum oil pan is more bulky.

The aluminum block LS bases motor would be stout but it is uncharted ground.

 

While the AX15 is a great transmission, it leaves allot to be desired in the gearing department and is not a cheap swap by any means.
The later NV4500's with 5.61 1st gear are not hard to come by and give you allot more bang for your buck in the gearing department. The NV4500 OD ratio is better than the AX15, lowering your freeway engine speed by 200 RPM.....
If you were to assemble an NV4500, D300 and axles with 4.88 gears, you'd be looking at a rig with 72:1 crawl ratio and a 70 MPH cruise speed @ 2461 RPM.
That same package with the addition of low max 4:1 gears in the D300 puts you at 110:1 crawl..... probably more than you need, but it really opens up your wheeling options!
2nd gear on the NV4500 is 3.04.... in 4 low with low max gears your crawl ratio would be 59:1.
Either way that is allot of bang for your buck with a $20K budget.

 

IMO, if you have the room, and the money, I’d run a doubler. When you commit to having the option of a super low range and a streetable high range, it leaves a gap where you’ll be stopping often to switch back and forth from low to high.

So here’s my solution. Start with a standard, non-Rubicon TJ and stretch it. Sell the body to recoup some cost. And fund the CJ6 body purchase.

I know someone a going to say, “Why a TJ and not an LJ, since the wheelbase is already 103”, the same as an intermediate 6…”
Because first of all, they’re rare and expensive. But more importantly, you don’t want to be pigeonholed into that wheelbase. If you run a 103” wheelbase on an intermediate on 35s, it won’t be enough. The rear tires will rub, and the front tires will have overbite. 104-105” would be ideal to fit the engine under an intermediate front clip while keeping the tires centered in the wheel wells.

When going that route, the engine, trans, and t-case are already reliable and done. Add that 2.72:1 Rubicrawler doubler for $2k and be finished with the drivetrain. The axles will be good enough to get you going, maybe plan on an 8.8 swap down the road. You’ll have three gear ranges covering every possible situation, and plush coils rather than harsh leaf springs.

If you can find a Rubicon in a decent price range, you’ll get the (marginally) upgraded axles. (The only real benefit is the lockers. The tubes are garbage.) Sell the t-case or trade +cash for a standard one for the best gearing options with the doubler.

 

I would use the TR-4050 transmission.

 

Having gone that route, that’s WAY more involved than what I proposed. They are anything but turnkey.

I wish you were closer.

 

In my little head I would start spending your money with an aluminum block LS and work from there. I do love my 225 but if this is a clean sheet of paper build, I would start with a modern V8. Gearing is great (necessary) but there is no replacement for displacement. For a CJ6 wheelbase, I would find a modern transmission (6 speed or more?) that gives a granny low 1st but was still made in this century, hopefully something still available (thinking of parts avail.). Mate that to your choice of TC. Working from that OAL decide if the short nose front end can still be used. I think I would go with the intermediate, the additional under hood room for a V8 with power steering/brakes while leaving the front open for winch of choice would be hard to pass on.

Of course, if the conversation is about a hypothetical CJ6 frame (already setup for the V6) that already happens to be in your possession that might change the choices, but I would still go LS.
Does Jen know about the new frame yet?

 

With the big face AA bell housing you could make an NV4500 bolt up with a little work.
Personally, I would set the 225 aside and opt for a more modern engine with factory installed EFI.
You already have one fairly original, vintage correct jeep and a hot rod style V8 swap wagon..... its time to build a wheeling machine!
If you are sticking with the short nose, pre 72 jeeps, I would opt for a 4.3 V6.
.

 

For me, if you are keeping the 225, that would force me to keep it simple stupid (KISS). 225>sm465 or 420>d18 with OD (3.15 gears is a bonus), front D30 with open knuckles and 30 spline offset 44 (if budget permits, convert 19 spline 44 to 30 spline with full float kit).

Looking at your signature, it seems you already have a similar arrangement in a CJ5.

next would be "modern" 4.3>ax-15>NWF under drive>d300 (bonus with 4:1)>narrow track D30/D44 (this is what I keep landing on as a good mix for ease of build, parts, and skill).

Full out, 5.3 LS>nv4500>d300 with 4:1>F&R 44 But the time to squeeze a 5.3 in an early jeep would be more painstaking than I want to tackle. since we're theorizing, I'll just build a scrambler with an LS haha!

 

This is why I want to build a CJ6, classic looks with modern drivetrain. I want to drive it on the highway and be capable off road.

I think I landed on an LV3 4.3 V6>ax-15>underdrive>d300>intermediate axles.

 

This is certainly interesting!

https://northwestfab.com/products/b...13411&pr_ref_pid=7967664570531&pr_seq=uniform

 

I want to see this....

 

I was building that in an Aqualu scrambler, but with an auto.