The Stovebolt Site Forums The Shop Area Engine Shop Rear-end Swap

In order to drive my '50 3/4-ton at highway speeds, is it possible to simply(?) swap the entire rear-end with an 8-lug '79 3/4 ton chevy rear end with a 3:73 gear. This would seem to be the simplest way to improve speed and update the brakes. I have also read that the guts from a 67-72 C20 rear-end will bolt right in to my existing differential. Is this true?

Yes, it will. Your ratio in your truck will have either a 5:14 or a 4:56.I have three 4:11 diffs sitting in my basement/garage.Email me directly or we may get in trouble for not doing business in the swap-meet!

Pumpkin swap is the easiest. Problem with the complete differential swap is the newer models are 3.5" wider than the AD. Narrowing would involve cutting and welding the housing and possibly having to recut the splines on the axles.

Out in the flat lands of IN i would go with at least a 3:55 .The 3:73 and 4:11 is still to much gear for a highway driven truck with NO o/drive.(unless your gonna load it good or tow a car trailer or somethin) You will get guys to tell yah they are runnin 73's but go ride in there truck before you do it.

A truck is for hauling we don`t make them into cars here!!!

Some of us actully own a truck that we could go 25,000 miles a year in. :p When was the last load your truck hauled. 2 crate motors day before x-mas.(at the same time,not bad for a car) He He He.Cant wait to feel better gettin ready to butcher a 18,000 miles 48 chevy 1/2 tonner. Yah one more purist mobile that wont have to go to parades any more or set in a garage with a cover waitin for the owner to die. I love my JOB.

You will have nightmares after cutting that one up!

You will have nightmares after cutting that one up!


The last load my 48 hauled was several exrta large loads of wet oak and 5,320lbs of scrap iron from fords!

Go and molest a **** !!!

It dont matter much to me what brand as long as it aint rusty. I do have a 48 FQRD coming in march so.......i butcher them as they come.Dont know why so many trucks latly.Before 5 years ago i did one truck a year now its about 2/3 of the bussiness.

Rows of over restored shiney black painted frame stockers parked next to 350/350 tilt wheel,wet look paint job, low profile tire customs.Its make ya so sleepy.How about some real vehicles with dirt and faded paint for a change.

Oh, so you want my 48 1-ton!

Absolutely, so long as it has faded paint,bird crap, and mud or manure on the under carriage.An interior you can sit in with tools in your pocket and wash out with a hose is a nice touch also.

Well, I wased the bird-crap off, but it does have some mossy algae type stuff growing on it!

dirt and faded paint = one lazy person.
The name of the game is quality NOT quanty.
I would rather have one nice truck than 3-10 worn out ugly barely running trucks(really anything).Worse yet field trucks that will NEVER see the road till the owner dies.Thats were rodder's come in and fix the mess the purist's made by leaving them undrivable and rusting away till they are SAVED.Cant wait to start cuttin on that 18,000 mile AD next week.(purist has only been in his grave for 5 months and i allready go it) :p :p :p NEXT!!!!!Well their goes another topic out of control

Dirt and faded paint is great.I have four running old trucks. Three of them are never washed.All of them run and run well and and can be driven cross country no problem.Yup quanity counts for me.Thats 4 less trucks turned into boring customs.

Tony you dont count.Your a middle of the road guy.Nothing you own is stock yet it aint modded a lot to get you tossed out of the purist ranking(well maybe the wife's truck but dont tell her she has a hacked custom cause she would have a bird). What is with the cross country crap all the sudden.You only drive your stuff about 4-5 months of the year to 2 events ,that's parade trucks. Come on nobody will laugh at your paint job.Hey i drove the old truck today in the snow,better than having a boring garage/barn queen.(who am i to talk ,at least your wifes hacked custom is painted) Besides goodhabit badhabit will have that collection of rust sold to a guy like me in a heart beat when you kick the bucket. Than let the hacking begin YAH!!!!!!

The cross country trip has been being planned for years but there was always an excuse. Working OT , gotta do this or that. No excuses this year. 2.76 gears going in.But I ain't pullin the trailer out there. Oh yeah the rear end gears, Joys 51 has 3.42 gears, pulled the 1500 lbs travel trailer just fine with the 235 engine that was in it.

[ 01-08-2002: Message edited by: Tony ]

Phat, you been sampling some of Olys crops? Not a harsh word in over a dozen posts! Must be mellowing in your old age . . .

I like the old rigs that are well taken care of with or without decent paint. I would have a hard time hacking up my 35 or the 49 that I have right now, but if it is a piece of crap truck that someone just let sit for years and isn't worth trying to bring back to original . . . I wouldn't feel bad about making it into a streetable rig with updated running gear / brakes / interior. Hot inlines are more my taste now, but in a year it might be V8's again or V6's or whatever . . . might do an electric someday!

Back to rear ends . . . what is the closest match to width for a swap on an AD that gives you 6 lugs? The 80's blazers are an inch wider . . . would this still look ok with 15" original looking rims / hub caps / rings with like a 235R15 tire?

Ken You will never see me sample Oily crops as i hate the stuff and see what it does to most guys.Not gettin mellowing either,just sick as a dog and gettin real bored with hangin around. The 80's rear works great,Unless i dump all the air out of the air ride and run it down on the bump stops the tires never come close(i suspect you will never run it that low).6 lug plus in the 80's you can find 2:73's to 4:11's just check the axles as the bearings stay in the housing and ride on the shaft .Have seen some that are worn pretty good.(takes about 20 min to remove both axles for inspection) I have welded them up and cleaned them back to size on the lathe but it may not be the best idea . The 2 wheel drive is the same but it has 5 lugs(easy to redrill) Watch out for the vans as they are much wider.I would never cut your 35 as i have not seen to many.But the 49 would be history to many of them around .

Hey Phat if cuttin and welding is all you know, can you weld up a bad bolt and then cut new SAE left hand threads? If that 48 has original 16 inch rims, and if thay are the same as 50 then send them my way. I need to get rid of these kid mags to make mine stock.

Phat et al,

Cain't say I'm fond of cuttin' virgin tin, but I'm not crazy 'bout old grumps lettin' good stuff sit in the field or the barn 'til it (or the owner) rots beyond help! :rolleyes:

I guess nobody likes rust!

I reckon I'll have to develop some weldin' & fabricatin' skills so's I can fix-up all the rusted-out AD cabs that the "choppers" won't touch .

(Are there really too many nice ADs, Phat? They sure aren't around me!)

So, back to the thread: punkin-wise, is there a definitive answer on which carriers directly bolt-on to the '47-'54 3/4-1 ton axle housing?
I've heard evrything from '47-'72, pre-'67 only, etc.

Frank nothing i would buy ,too much money.The guys around here will pay 3-6 grand for a truck with no rust in the cab and bent up fenders.The 18,000miler i think he paid 6500 bucks for but there wont be any patch panels on it so.....a lot less welding.(welding = bucks).

Well there you go Phat.Gotta stick to the junk and the big labor profit.Do em in reverse,cut out the hot rod stuff and turn the truck back into stock.