I am going to do it ! J/10 shortbed stepside !

[AMC-J/20]

I am going to be picking up myself a J-truck !

I want to make it a J/20, what will I need ?

Mike

[FSJK]

a LONG bed
8 lug front 44 & 8 lug rear 60
heavier duty springs
emblems


(why not just put in stronger axles, airbags in the rear, and leave it a 'j10'?

[AMC-J/20]

Lol ok ok, I want a shortbed stepside J/20 funny guy . . . I want the 8 lug wheels and heavy spring axle combo.

Do they just swap over ?
Mike

[itselliot]

Sent you a PM

[Elliott]

Depending on the year ranges you mix parts from it'll all swap but the rear driveshaft, ebrake lines I think.

[AMC-J/20]

So it won't work ?

Or

Rear shaft would have to be made ?


Mike

[jaber]

If they are from close years, it should be easy. If there are a few years different, then you might run into fitment issues...

[Elliott]

Originally Posted by AMC-J/20

So it won't work ?

Or

Rear shaft would have to be made ?


Mike

Just get a J20 driveshaft and have it cut down, re-balanced or use the shorter J10 to have re-tubed and balanced.

[AMC-J/20]

So it'll go from D44/D44 6lug to a D44/D60 8lug ?
Now one last question could a D60/D60 8lug combo be done ?

Mike

[rocklaurence]

I have J20 axles on my J10 long bed (bought from Hoot during a Xmas delivery). The DS will need shortened 2". It cost me $80. IMO, keep the J10 springs and add air assist if needed. The J10 rides like a Sled. So, why make it worse? Plus, if your going to lift it, the springs are the same. Lastly, where's the pictures!

[AMC-J/20]

Oh I can leave the J/10 springs ? and swap axles ? Just want the 8lug hubs for my nice 8lug wheels I wanna run ;-) !

Now as photos ! There will be tons n tons in plenty o time ! I'm more excited then anybody !


Mike

[jaber]

OK, so wheres the pics...

We are waiting....

[AMC-J/20]

I'm working on it trust me guys !

Mike

[Elliott]

Originally Posted by AMC-J/20

Oh I can leave the J/10 springs ? and swap axles ?

Yep, the D60 u-bolts and plates are axle specific due to the larger tubes. If you were to swap a D60 up front they are a bolt on also, however, the springs mount on top giving you ~6.5" of lift to adjust for in a number of ways and the steering needs to hook up differently so you are looking at a number of changes to do it.

[AMC-J/20]

So D44/D60 8lug is direct switch over Coolness . . . but for a D60/D60 = 6.5" lift ok D60 front is out want a fairly stock stance !

Not much of a lifted truck guy, it already has 33s on it which is ok cause the new wheel/tire combo will fit just fine then !

245/70R19.5 = 33.3" tall
Mike

[lycanthrope]

j10mike's truck is very popular here. read this and then tell us how close your plans would come.

New Page 1

[AMC-J/20]

Not even close the body n grill is about all our trucks will have in common no offense ment.
His Rig tho nice is still off road ish. My truck will be more tow rig ish ;-) !

I will running tires like the 450/4500-550/5500's have only on polished aluminum Single rims 1 tire size bigger . . . I'll have the only or one of very few short bed step sides capable of towing a goose neck/fifth wheel trailer ! :-) !

The guy I am buying from is keeping the rear fenders, So I will be running some custom fenders that'll resemble that of a deuce n a half's front fenders !

AMC-390/ 4-5spd manual/ D44-D60 with 4.10-4.27s / 245/70R19.5s !

4spd = 4.10s / 5spd = 4.27s.

Sporty looking work horse going to be used to haul my AMX and what ever else I wanna hitch to it ;-)

Mike

[Towtruck]

I've routinely towed Javelin sized cars with a bumper style hitch for years. While the gooseneck hitch that I installed 20 years ago certainly does a better job for a short wheelbase truck, it's not mandatory...plus I don't have enough space to keep a gooseneck trailer.

With the tongue weight farther forward on a gooseneck you for sure don't want (or need) J20 springs. Airbags for towing make perfect sense, although my J10 does fine with stock springs and these relatively light weight cars.

Make sure that tire/wheel/axle ratio is matched to the engine torque/power characteristics...you'll likely tow in 4th gear even with a five speed. Look for a transmission with close 3rd to 4th ratios...the T-18 and NV4500 have a big gap. Sounds like you're specing the truck around a set of bling wheels...

I'm a fan of rear disk brakes after experiencing some nasty uneven braking in the wet with drums.

[AMC-J/20]

I'm sure it'll tow the car fine in stock form with a tired 258 I6, I just know how the truck will get loaded from time to time.
I am sure in no time I will be towing loads around the farm that would sag a GM C/K-30

I was thinking about bags, also thought about J/10 springs on front and J/20 springs in rear.
Bags would allow me to drive it like 1/2 empty and work like a 1ton loaded ?

Over built is in my nature
Mike

[Tinkerjeep]

Well, since I made a 131" wheelbase 1979 J20 INTO a 119" wheel base 1979 J10, I don't see why you couldn't do it BACKWARDS. You aren't moving any of the rear spring hangers, so use J10 leaf springs and rear driveshaft. Both rear axles (exisiting and new) should be from Jtrucks with the same transfer case or else the pumpkin offset will be different.

Here's pics and a looooooong write up...

http://rides.jpmagazine.com/ride/119...kup/index.html


On my J20/10 I not only channelled 12" of framerail out of my J20 frame, but I chopped 6" off the rear of it and welded in a new rear crossmember. Then I channelled 9" of bed length out of it behind the rear wheelwells - so its "Bob-tailed".

Front axle/suspension - I just mounted the front J20 springs up front (heavier duty at 3500 pounds rating vs the 3200 rating of the stock J10 springs) mounted the front Dana44 to those.

Rear - Mounted reinforced J10 rear spring packs (P.O. added an extra top leaf to each pack with Spring eyes cut off) to the rear and bolted rear Dana44 to those. Had some minor Springpack/Frame-boss rubbing at full flex at first, but it "self clearanced" after a couple good runs. This combo flexes more than J20 (7600 GVWR) springs like my 4-door J-truck has and my 30x11.50x15 B-Rated Swamper TSL-SXs handle my driving style just fine. Think Muscle-Car-handling, NOT Corvette-handling. Totally predictable and fun to drive. Probably bottom-out if I hit a curb strait on at speed though

Transfer case - Borg-Warner Quadratrac, and front driveshaft is swappable between the J10 and J20.

The rear Driveshaft is up to you. The same spicer U-joints for front and rear of J10 and J20 are the same (don't recall the number now) but trust me, I had them installed in a J20 Driveshaft, didn't run it, pulled them and reinstalled them in my J10 Driveshaft - same-same. HOWEVER the J20 DS tubing is obviously beefier...4" (I think) diameter instead of the 3" tubing (I think) for the J10 shaft. I just reused the J10 rear D.S. instead of cutting down the J20 shaft.

Motor - torque issues - My J-2010 only has a tired 360 4v with Edelbrock intake and 1405 carb on it. I don't know how much power it makes, (not much) but its driveable - I don't tow with it - its a sorta-daily-driver. I plan on building up a 1978 401 I got for $50 to about 300-400 hp to plop in this truck, I might rethink the rear driveline then. The "Street" 1971 401 made about 330 hp, the 390 made about 340, and the 360 was about 315 (I think), not much difference but the torque output of the 390/401 was more plentiful and came in at lower RPM. AMC 390s are about non-existant now, and were never offered in Jeeps. The later 401s were dogs - equipped with a stupid cam which made 100 lb/ft LESS torque than the Edelbrock AMC Performer cam! (The stock 360 cam has better specs and would make good numbers in a 401) The AMC performance package (Cam, intake, carb) roughly duplicates the performance available in the 1971 401, with their iron heads, exhaust manifolds, and dual pipes. With 450 lb/ft of torque available at around 1,500-4,500 rpm, the rear DS might need to be replaced with a cut-down J20 shaft If a guy driving a Quadratrac-ed J20/10 likes to stand on the loud pedal from a dead stop in his 4500 pound truck...driveshaft carnage may occur... Food for thought.