The Stovebolt Site Forums The Parking Lot Big Bolts rear end swap info

i REALLY don't like the rear end ratio in the 51 ton and a half. at 48 m.p.h. i'm a road hazard. i have been looking for a late model differential from a 3500 gmc to swap so i could keep all the wheels at the current 10 bolt pattern. no luck. yesterday i found a late 60's or early 70's step van with a 10 bolt pattern on 18 inch wheels. it looks like the samwe bolt pattern as what's on the 51, and is single speed.
any of you guys know if the wheels are the same bolt pattern? how about spring perch width and driveshaft compatibility? the step van has a 6 banger, manual shift, and i think has a 4:11 ratio. at least i could zip along at 55 or so with the 10:00x20 wheels and tires.

i gotta move fast on this one, as the guy at the bone yard is gonna crush the thing.

When you find the solution can you let me know... I don't have the advantage you have of looking in boneyards at the top of Australia.

I am wondering whether or not new diff gears could be made to suit by an engineer.

Cheers
Jason.

I believe the bolt pattern is the same but the stud size is larger. Measure the center hole. there is variation on those. You can drill your stud holes out to match. The spring perches will likely have to be relocated. Measure backing plate to backing plate. Prabably prety close. Most of those had 4:11 gears. We used to drive them 65-70 all day long.

Hey Kool, You've got 10.00X20's on that 350 COE of yours. WOW !, That 'ol boy's sitting high. I was thinking about putting 10.00X20's on my 450 COE, but I don't think my Holmes W45 Wrecker rear fenders, will clear them. You're cutting yourself short, on the gvw. That 350 series of yours, is a 2 ton. 300 series GMC's, were 1 1/2 ton rated.

i messed up spanky. i got 900x20's. yaknow, you got the truck i really wanted. i wanted a cannonball type truck when i got the coe i have. i figured that was as close as i wuz gonna get. my real dream was a 3 banger diesal with an allisons behind it. i wanted the fenders to open up so's a guy could get in there to work.

5 inch exhaust and a jake brake and WHOOO-HOOO!

I have a Dana 70HD under my 1952 1 ton pickup. it is from an 88 P30 truck. It has 10 lug on 7.25" with a 5.25" hole in the center. I believe if you wanted to use the original wheels from 1.5 or 2 ton you would have to bore out the centers either 0.375" or 0.75" I forget.

So it looks like the same thing on the ends as the original trucks, but it does have 13.5" disc brakes and the option of gears as fast as 3.54 to 1.

I know it is under a 1 ton now, but I set it up with 2.5" springs as if it were under a 1.5 or 2 ton. I am currently looking for one of those with good sheet metal and I will switch my running gear over and then probably go with dual wheels and not my singles.

I am also running the same disc brakes up front and a new hydrobooster for the brakes and power steering too. Still a 235 6 for now, in the future I am going with a 4 cylinder diesel.

It is a very dependable truck, I drove it around the country last summer, about 8,000 miles, with only a broken fan and bad generator bearing to slow me down.

If I can figure out how to add a picture I will, any ideas?

well, since i am a confessed computer idiot, just e-mail them pictures to mom. uhhhhhhhh, peg that is. i bet she can get them pictures up and on the board.

by the way, thanks, good idea!

here are some pictures,
http://www.stovebolt.com/gallery/mullen_grigg_1952.htm
also search the other post for "Dana 70HD" I have posted in some others about this as well.

What else would you like to know about mine?

i have a dana 70 sitting around. it's a duel wheel off a 1 ton ambulance with 8 lug pattern and drum brakes. do you know if i can find 10 lug pattern drums and centers that will fit?

other than that, i'm thinking about some kind of wheel adapters from 8 to 10 lug pattern.

a picture of the truck i want to put this on is at

webshots. com

type in koolkar100

then look under all pictures.

oh yeah------helluva good job on yer hot rod!

Spanky,

Thanks for helping with Koolkar's images. They never made it here to the house

Peg

hey coolkar that coe looks cool up in the air like it is

thanks spanky! ashton, that old coe is gonna stay in the air! i just wanna make it alittle more highway friendly without changing the looks. that's why i'm looking at swapping the differential, but keeping the big wheels.

i've alsoo been looking for a chebby with a single speed rear and trying to locate a higher ring and pinion for it.

My guess as to finding 10 lug hubs and drums for an ordinary Dana 70 is that there aren't any.

A Dana 70HD like mine uses 4" tubes not 3.5" like yours, and from what I have been told the outer ends (spindles and hubs) are of the Dana 80 size.

So, unless a Dana 70 normal was made with 10 lugs you are out of luck.

While I have ya here-I just ran across a Dana ?? rear end in a 1969 Ford mini-motorhome;you know-the ones that use a 1 ton van front group.It has single wheels,but the wheel studs look long enough for me to run duals on it. I took a pair of my wheels (from a '66 one ton Chevy)to try on it,to check clearance around the drums,but my wheels won't fit over the axle. The center hole is too small,by maybe a quarter inch. I also noticed I'd have to drill out the stud holes,but that's no big deal. The questions are:What axle does this sound like it is? Would it be worth the hassle to cobvert it to work in my '62 one ton duallie? It'll cost 150.00 to get it,but if it'll be a good match for my truck,I'll try to do it.

Is the gear ratio the same or is it one you can live with? The price seems to be in line...

Mike

Forgive me if this sounds totally stupid.. but isn't the purpose of having a two speed rear end so that you can get higher highway speeds?

If thats the case, couldn't you just find a two speed rear end out of a simular year vehicle and just swap out the rear axle?

Theres a dude with a yard down the road from me who has several 50's 1.5 and 2 ton trucks, and has a few GMC axles (both vac 2 speed and "regular") already chopped out.. don't know if those would do you any good, or if getting one from western Nebraska would even be cost effective, but you could probably get 'em cheap.

Actually, I think the purpose of the 2-speed rear was to get more low end pulling power using the lower ratio. The high ratio was about the same that came in the single-speed rears for the Chevy 5-6000 series trucks. I'm assuming GMC is similar.

From what I've seen, the single-speed rear axles are close to the average of the high/low ratios of the 2-speed rears.