'72 to '68 axle swap question.....

[MotorSeven]

Ok, i researched here and found that the 72 axles will be 3/4 inch longer than the 68. My neighbor(an old school Mech) says that they will work, soooo i pulled a pair out of one in a local bone yard. Yep, they are longer, however, the drum from the 72 is 3/4 inch deeper.
My question is : Can i slap the 72 drums on the 72 axle in the 68 housing? It seems to me that as long as the bearing surface mates up and the brake shoes are covered it should work ...right? Anyone tried it?
This is just a temp fix, because i want to get the truck on the road....my rebuilt 350 is sitting on the garage floor looking very lonely........Eventually i am going to put in a posi.

RD

[ksjh1316]

Man I wish I had the answer but its some more of the info I am looking for GL I will be watching as well.

PS Thanks for the rain measurement last night

[Brad]

It'll work, but the axles are hardened only on the original bearing surfaces meaning that when you have the new setup, the bearings won't be riding on a hardened surface anymore. You run a serious risk of the axles breaking. It'll probably be fine if only used for a few months or so.

[Longhorn Man]

plus, there will be more leverage on the axle right by the bearing.
Many ppl have done it and gotten away with it.
I'd hate to have one snap at 70 MPH on the way to work.

[Jim_PA]

I drove mine that way for over a year with no problems.

I ended up getting the 2 3/4 inch drums from like a 78 chevy or something...

Since then I put in a 72 posi rear, and went back to the 2" rear brakes.

I would only recommend it if you've got a line on some cheap big drums, and just want to get it on the road -- or if you plan on upgrading your backing plates when you go to the "correct" axle width, and keep the bigger rear brake drums.

I ended up buying 2 new sets of drums- one 2 3/4" set when I had the longer axles in, then.... when I went to the 72 rear, I had to buy a 2" set... Those things aren't cheap, but I was at the point of either getting all new backing plates and shoes to use my 2 3/4" drums, or just suck it up, and buy 2" drums for the 2" shoes and backing plates I already had on there. I don't think they had the wider shoes/drums in 72, unless there was a heavy-duty brake upgrade I wasn't aware of.

I hope that wasn't too confusing...

[MotorSeven]

Hmmm, ok, thanks for the info, and i have to add....ARGGG! It looks loike i have to go back to the bone yard and get the rest of the rear end, but it's a 100 bucks as opposed to 40. I am going to start scrounging for a posi. Is there anyway to tell from the outside? And will a later model posi work? Sorry if this has been covered before......

RD

[Jim_PA]

Originally Posted by MotorSeven

Hmmm, ok, thanks for the info, and i have to add....ARGGG! It looks loike i have to go back to the bone yard and get the rest of the rear end, but it's a 100 bucks as opposed to 40. I am going to start scrounging for a posi. Is there anyway to tell from the outside? And will a later model posi work? Sorry if this has been covered before......

RD

No sure way to tell, and yes any 12 bolt truck posi will work, as long it is the same carrier series as the gears you want to use. I would look for one with clutches and springs as opposed to the type with weights (gov lock).

[MotorSeven]

Since it stopped raining, and it ain't dark, i put the two axles side by side and measured from the clip grove to the bearing surface. The 72 axle has a longer bearing surface which will allow the bearings to ride entirely on the hardened surface with 1/8" to spare. Larger drums won't be a problem, and i think i can run this set up until i can find posi.

Now i have to get the 305 out, swap the front end, drop the 350 in. Thanks to JerseyGirl, i have a free set of headers, and i decided i am going with glasspacks.....takes me back to the "good ole days!"

RD