Jeep Bench Racing, building a "new" Willys CJ2a

Greg

I run a tight ship... wreck
Admin
Just for discussion...

So when I was out at Rabbit Valley cruising around in my 70 year old 1948 Willys CJ2a, my mind started thinking about the idea of building a Willys that looked pretty close to a factory original from the 40's and 50's with new parts, but with some big improvements that would make it more driveable and capable. It's hard to find a clean Willys these days, most of the bodies are rotting away, frames are in rough shape, etc.

There is a company by the name of MDJuan out of the Philippines that is making reproduction parts, they say their parts are exact copies of the originals but in the past, people that have bought them have found certain parts to be off just enough to cause problems. Others have said that the aftermarket parts and original parts don't quite work well together.... so take that for what it is. That said.... you can get a reproduction frame and body kit with free shipping for a very reasonable price. Sounds like if you use all reproduction parts, they should work well together. The basic body kit doesn't include a lot of the small parts you'll need, also missing the grill. The master body kit seems to contain just about everything you need to assemble the body, but it's not cheap. Still, the master kit + a frame is just over $6k and that's not bad for a 'new' CJ2a.

Frame is $1350 - https://www.quadratec.com/p/md-juan/chassis-assembly-45-49-jeep-willys-cj-2a

Body kit is $3000 - https://www.quadratec.com/products/42500_15D_T.htm

Master Body Kit is $5000- https://www.quadratec.com/products/42500_1000_07.htm


So here's my thought.... set up the 'new' Willys with a GM Vortec (or TBI) 4.3, TH350 and adapt it to a rebuild Dana 18/20/300. Fuel injection, V6 power and modern reliability would be great. The automatic trans would make it easy to drive. Rebuilt a set of early CJ5 axles (Dana 30 and 44), add disc brakes, you'd gain locking hubs, 1 piece axle shafts, etc. 4.10 gears would be decent offroad with the auto and still allow driving at 60+ MPH without overdrive. Add Saginaw power steering to make cruising around effortless. Get a set of custom springs built (Alcan?) with 2" of lift and make them 6" longer on the frame end and extend the spring mount, that'll ride better on road and make for more wheel-travel offroad. Extend the shock mounts on the frame for a longer shock, to match the springs. Set it up with a set of skinny 32" tires and period-correct wheels to finish it off!

Obviously there are hundereds of ways you could build a 'new' Willys... modern 4 cyl engine, mated to a rebuilt T90... small 4 cyl diesel engine, etc, etc, etc. How would you piece together a reproduction Vintage Jeep?

I would love to tackle something like this down the road, but for now I'll just have to keep tinkering with my original. ;)
 

Hickey

Burn-barrel enthusiast
Supporting Member
I've thought of this a lot lately, only with a CJ5.

For your CJ2A, the stock frame width may be an issue if you want a flat belly skid plate. The 76 and later frames were wider at the rear, and even then it was pretty tight when I made my old CJ5 flat belly and routing the exhaust.

I think the engine choice would be the most difficult for me. I really want a modern V8 in it, but drive train total length would be a serious issue.
 

Greg

I run a tight ship... wreck
Admin
I've thought of this a lot lately, only with a CJ5.

For your CJ2A, the stock frame width may be an issue if you want a flat belly skid plate. The 76 and later frames were wider at the rear, and even then it was pretty tight when I made my old CJ5 flat belly and routing the exhaust.

I think the engine choice would be the most difficult for me. I really want a modern V8 in it, but drive train total length would be a serious issue.

I know you can get reprod CJ5 bodies, not sure how hard frames are to find new. You could probably still find a decent 76+ frame, strip it down and clean it up, then pair it with a new body. Looks like they have quite a selection of CJ5 parts! - http://mdjuan.com.ph/civilian/?model=cj5

It wouldn't be hard to fit a V8 (LS engine anyone?!) into a CJ5, but having an overdrive as well might be difficult. My '80 CJ5 had a SBC with a factory SR4 4 speed and the elusive 'short' Dana 300. The engine fit great, kept the trans, t-case and driveshaft in the factory location.


I think you're right on track with the 4.10 gears and the TH350 for highway/trail balance.

Yeah, that's how my CJ5 was setup.... no over drive, 4.10 gears and 32" tires. I could drive it on the freeway at 65 MPH, but the engine was screaming. :eek:
 

Greg

I run a tight ship... wreck
Admin
I think the engine choice would be the most difficult for me...

That Kubota diesel engine swap you mentioned awhile ago would be a pretty neat option, especially if you loved diesels, as I do! You could run a rebuilt T90 transmission with a Dana 18 and a Warn Overdrive. And they offer a turbo kit for the Kubota for even more power!

That would be a neat setup in a 'new' CJ2a, wonder where gearing would be best? 4.10's sound good w/o an OD, but not sure how well the Kubota would do.

https://www.overlanddiesel.com/conversion_kits.html

https://www.overlanddiesel.com/turbo_charger.html
 

Greg

I run a tight ship... wreck
Admin
Throttle Down Customs makes incredible mandrel-bent rectangle frame rails from 2"x4" 3/16" which look amazing. Obviously a lot of fab work to make into a usable frame.

http://www.throttledownkustoms.com/i-26373457-jeep-frame-rails.html

F161156273.jpg



Sounds like they also make a complete frame with cross members, but no pic or further info. - http://www.throttledownkustoms.com/i-26373460-cj-2a-jeep-frame.html?ref=category:1331223
 

Greg

I run a tight ship... wreck
Admin
Having polished a few Dana 300, I’d just buy an Atlas. Probably to long but the D300 is pretty “meh” to me

I think a Dana 18/20/300 would be perfectly fine for a stock-ish Willys with a GM 4.3 and small tires. Atlas would be neat, but totally overkill for the scope of what we're talking about, IMO.
 

mbryson

.......a few dollars more
Supporting Member
Something to be said for being light and less leverage from the tires. I’m just kind of tired of my Dana 300. Parts aren’t hard to find but you do have to seek them out.

Atlas (if you could fit it) would NEVER break in that rig. D300 may or may not?

I’m basically doing the same kind of build with my MJ? Different platform but philosophy is similar. Keep it lower powered, light(ish-i have a 4.0L-nothing light about that beast), and keep the tire size down to make the axles live. I have WAY more wheelbase and less cool factor.

An overdrive trans could be nice. Shrink-ray TJ (Verne Simons) comes to mind as a modern version of what you’re thinking?

I don’t know exactly how fast you’d want to run in a rig like this? 75 would be really flying? I wonder if you used 3.90 gears with 32-33” tires and a T350 or short manual trans if that might be the way to go? If you had a 3:1 tcase, that would make those gears sustainable off road and be useful on road? 3.73 might be to low? Max speed would still be about 65-70 or a little less?

I like the 4.3L or Buick 3.8L (bonus points if you added fuel injection to an odd fire) as a short power plant. 200r4 should be shorter than it’s 700r4 cousin. I’ve not seen that in a 4x4 (Maybe there’s a reason for it?)
 

I Lean

Mbryson's hairdresser
Vendor
Location
Utah
I was just going to say...I wouldn't bother with a stock-reproduction frame. The open-channel design is light, but not very strong--which makes it crack-prone. The TDK frame rails would be awfully neat under there.
 

RockChucker

Well-Known Member
Location
Highland
Sounds like what you are describing is kind of embodied in the latest rig Bentley Garner is building for a customer. Check it out. Tj tub and frame with some Willys flare and grille. He bobbed 9" off the back and close to that out of the hood length. Even more off the frame. Check out his instagram for the details. @bentleygarner
 

Greg

I run a tight ship... wreck
Admin
Something to be said for being light and less leverage from the tires. I’m just kind of tired of my Dana 300. Parts aren’t hard to find but you do have to seek them out.

Atlas (if you could fit it) would NEVER break in that rig. D300 may or may not?

I’m basically doing the same kind of build with my MJ? Different platform but philosophy is similar. Keep it lower powered, light(ish-i have a 4.0L-nothing light about that beast), and keep the tire size down to make the axles live. I have WAY more wheelbase and less cool factor.

An overdrive trans could be nice. Shrink-ray TJ (Verne Simons) comes to mind as a modern version of what you’re thinking?

I don’t know exactly how fast you’d want to run in a rig like this? 75 would be really flying? I wonder if you used 3.90 gears with 32-33” tires and a T350 or short manual trans if that might be the way to go? If you had a 3:1 tcase, that would make those gears sustainable off road and be useful on road? 3.73 might be to low? Max speed would still be about 65-70 or a little less?

I like the 4.3L or Buick 3.8L (bonus points if you added fuel injection to an odd fire) as a short power plant. 200r4 should be shorter than it’s 700r4 cousin. I’ve not seen that in a 4x4 (Maybe there’s a reason for it?)

Yeah, light and small... I wouldn't need anything to do over 60 MPH, but if it drove decently well at that point I think it would be a success!


Quick 200 research: no bueno. No removable tail shaft = no 4x4 applications other than divorced tcase... not ideal for a flatty

Yeah, they never made a 4WD 2004R, you can have one built, but.... $$$$


I was just going to say...I wouldn't bother with a stock-reproduction frame. The open-channel design is light, but not very strong--which makes it crack-prone. The TDK frame rails would be awfully neat under there.

Agreed... for a 'new' ground-up build, a beefer frame than stock would be best!


Sounds like what you are describing is kind of embodied in the latest rig Bentley Garner is building for a customer. Check it out. Tj tub and frame with some Willys flare and grille. He bobbed 9" off the back and close to that out of the hood length. Even more off the frame. Check out his instagram for the details. @bentleygarner

I have seen that build, Bentley is doing amazing work! The TJ frame is a pretty interesting idea, outside the box for sure.
 

smfulle

Active Member
Location
Plain City, UT
If you have a couple of days, read through Jeff’s build thread (all 70 pages) of his MB Bam Bam on thecj2apage.com. He’s done a lot of what you said in your first post. He’s also taken great care to make it look like he hasn’t done a thing to it. He hasn’t used much MD Juan stuff though. He can do 70 on the pavement all day long.

https://www.thecj2apage.com/forums/building-a-universal-modified_topic28473.html

JP and Crawl both did cover features on Bam Bam.

http://www.fourwheeler.com/features/1606-mighty-1943-wwii-military-jeep/

Come to the Flat Fender Fun Run at Easter Jeep Safari and watch Bam Bam work.
Jeff in Bam Bam and I in my mostly stock 48 CJ2A will be there in Moab all week. We’re staying in the Canyonlands campground in the back by the fence, Stop by in the evening and see us.

Here’s Jeff and Bam Bam doing some wheelin’ in Kansas.

 
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Hickey

Burn-barrel enthusiast
Supporting Member
The biggest difference with Bam Bam, is the manual transmission. An auto trans is significantly longer, if I remember correctly.

It wouldn't be hard to fit a V8 (LS engine anyone?!) into a CJ5, but having an overdrive as well might be difficult. My '80 CJ5 had a SBC with a factory SR4 4 speed and the elusive 'short' Dana 300. The engine fit great, kept the trans, t-case and driveshaft in the factory location.
Bit you didn't have an auto in your CJ5.
 

Greg

I run a tight ship... wreck
Admin
If you have a couple of days, read through Jeff’s build thread (all 70 pages) of his MB Bam Bam on thecj2apage.com. He’s done a lot of what you said in your first post. He’s also taken great care to make it look like he hasn’t done a thing to it. He hasn’t used much MD Juan stuff though. He can do 70 on the pavement all day long.

https://www.thecj2apage.com/forums/building-a-universal-modified_topic28473.html

JP and Crawl both did cover features on Bam Bam.

http://www.fourwheeler.com/features/1606-mighty-1943-wwii-military-jeep/

Come to the Flat Fender Fun Run at Easter Jeep Safari and watch Bam Bam work.
Jeff in Bam Bam and I in my mostly stock 48 CJ2A will be there in Moab all week. We’re staying in the Canyonlands campground in the back by the fence, Stop by in the evening and see us.

Here’s Jeff and Bam Bam doing some wheelin’ in Kansas.


I have read quite a bit of that thread, Bam Bam is an amazing build! I'll try stop by and BS!


The biggest difference with Bam Bam, is the manual transmission. An auto trans is significantly longer, if I remember correctly.

Bit you didn't have an auto in your CJ5.

Hey, you can't have your Cake and Eat it too! :p


4l60e is about the same length as the th350

Looks like 2" difference? That's not much!
 

Magerdgr

Have gun, will travel
I think a Dana 18/20/300 would be perfectly fine for a stock-ish Willys with a GM 4.3 and small tires. Atlas would be neat, but totally overkill for the scope of what we're talking about, IMO.

If you used one out of the '67-'72 with the dauntless they have a much bigger main shaft (1 1/8" I think) very solid case.
 
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