Smaller/thinner rear brake drum? Deep rear steelies won't fit!

[mongocanfly]

Washers...before you buy spacers
all you need is to stack some washers on the wheel studs to see if a spacer is gonna help you any
But before you commit to discs, I'd talk to the manufacturer of whichever one you chose to make sure itll work..

[geezer#99]

And then after all the planning, swapping and hair pulling you find that your chosen wheels and tires don’t fit your truck. Tires rubbing everywhere isn’t good.

Show us these wheels you’re wanting to use.

[vintage_mpg]

Originally Posted by geezer#99

Depending on the design of the backing plate you might need to pull the axles to change them out.

Maybe wheels that fit are the best option.

This is the best answer.

Here's why I'm pushing on this so hard: the PO purchased these custom wheels at tremendous cost based on his research with Squarebody Syndicate. According to him, the cost of the wheels and tires were right at $2200 for the set. He never got to use them, as he ran short on time trying to address this rear-wheel fitment issue...and when I picked up the truck, he just handed them to me, explaining what he had already run into.

SO - different wheels may be the only answer - but gosh, I'd sure love to see these bad boys on the truck. I'm hoping that I can figure it out without throwing the bathwater out with the baby....or something like that!

[geezer#99]

Post some more pics of the wheels.
Free stuff isn’t always free.

[Nick_R_23]

If you’re not even willing to perform the simple task of comparing your current drum to a new one from a local parts store to check for additional clearance with a new part, there’s not much left we can help you with. Sorry to sound rude, but that and other simple steps have been offered here by multiple members and you appear to ignore advice given.

[Pontiac1976]

The wheel is the problem, the biggest factory GM Truck steel sport wheel 15"x8"wide down 15x7 smallest 15x6. GM Vett rim had 10" most likely had the center welded it from a GM truck.
If you buy list of any rim 15x10 1/2 bolt spacing for a 73-87 1/2TON less time less money.

[vintage_mpg]

Originally Posted by Pontiac1976

The wheel is the problem, the biggest factory GM Truck steel sport wheel 15"x8"wide down 15x7 smallest 15x6. GM Vett rim had 10" most likely had the center welded it from a GM truck.
If you buy list of any rim 15x10 1/2 bolt spacing for a 73-87 1/2TON less time less money.

You're correct - it's all stemming from the wheels.

I think he mentioned that they were 10" wide, but I haven't measured to verify that. They're big and wide, for sure. The matching fronts are 8" wide, and they fit on perfectly.

I'm including a few more photos of the wheels, so as to give you an idea of what I'm working with. You'll see me pointing to the points that are rubbing on the brake drum; I started to take a grinder to the raised section this eve but just ran out of time. I'll keep working on it. This could be the absolute best solution of them all! Haha!

And hey - THANK YOU for all the great thoughts and suggestions! I'm getting closer with every passing post. I love this place!

[vintage_mpg]

I've also rounded up some 1/4" spacers to play with as well. That will help fill in the gaps that I'm chasing...

[geezer#99]

Hope your grinding doesn’t destroy the strength and/or balance of your rims.

[vintage_mpg]

Originally Posted by geezer#99

Hope your grinding doesn’t destroy the strength and/or balance of your rims.

I feel confident it won't change the integrity of the wheel itself, as I'm only touching the folded section of steel that is folded up and near the center of the wheel hub....however, it most definitely might compromise the balance of the wheels. I should have them rebalanced if this all comes together. That's actually a great idea - I appreciate you bringing that up!

I'm not sure I can even grind off enough to gain that clearance that I need....but I feel like it's worth a shot. The wheels aren't worth much as it is, and perhaps this will afford me just what I need to get this train rolling! Other than changing the shape of the extra steel inside the wheel, I think they'll be just fine.

[Warrens69GMC]

Originally Posted by Cptmoney

I'm not sure I can even grind off enough to gain that clearance .....

Why even try? Is the auto parts place 100 miles in each direction that you cant go and look at a replacement drum?

[vintage_mpg]

It's official: I have the 2 3/4" rear brake shoes!

[vintage_mpg]

Originally Posted by Warrens69GMC

Why even try? Is the auto parts place 100 miles in each direction that you cant go and look at a replacement drum?

It's not quite that far...but it's a decent distance.

A few more days and the parts store should have the drum. Then we can compare to what I've got now.

I can't help but believe that my current brakes are oem stuff. Not sure the replacement drum would look any different - but it's worth the look, just in case. It's a former state highway dept truck, so I feel confident that the brakes are factory-style stuff. That being said, let's have a peek at the replacement! Who knows? Maybe that's all I need!

[Pontiac1976]

That the better size shoes for braking going the other way is a down grade. that little bit extra does make you feel it on hills or towing, heavy loads on heavy on off breaking on hot days.

[vintage_mpg]

Originally Posted by Pontiac1976

That the better size shoes for braking going the other way is a down grade. that little bit extra does make you feel it on hills or towing, heavy loads on heavy on off breaking on hot days.

I imagine so.

That's what....37-38% more braking surface than the standard 2" shoe? I would imagine it's much better.

[mongocanfly]

depending on how much you need for clearance you might get away with machining some of that outer lip surface off the drum

[SCOTI]

Originally Posted by mongocanfly

depending on how much you need for clearance you might get away with machining some of that outer lip surface off the drum

This.

The HD drum has more perimeter material vs. a standard drum as well as being wider. It's possible some (enough?) material can be removed from the drum to offer enough clearance within the wheel hoop for the deeper rear 10" wheels. Those wheels should easily work on standard drums. A 16" x 10" wheel will clear the HD drums (I had them on the rear of my '64).

That being said.... Swapping between the HD setup & the standard drums is just removing the one & replacing it w/the other. I've done it on multiple trucks. Most wrecking yards will have trucks w/the standard stuff. The HD stuff is usually found under Blazers, Burbs, Diesel equipped, as well as specific optioned trucks.

[geezer#99]

Originally Posted by SCOTI

This.

The HD drum has more perimeter material vs. a standard drum as well as being wider. It's possible some (enough?) material can be removed from the drum to offer enough clearance within the wheel hoop for the deeper rear 10" wheels. Those wheels should easily work on standard drums. A 16" x 10" wheel will clear the HD drums (I had them on the rear of my '64).

That being said.... Swapping between the HD setup & the standard drums is just removing the one & replacing it w/the other. I've done it on multiple trucks. Most wrecking yards will have trucks w/the standard stuff. The HD stuff is usually found under Blazers, Burbs, Diesel equipped, as well as specific optioned trucks.

Did you need to pull the axles to remove the backing plates?

[vintage_mpg]

Originally Posted by geezer#99

Did you need to pull the axles to remove the backing plates?

I'm wondering the same thing.....

Almost have to, don't ya?

[SCOTI]

Yes.

[geezer#99]

Originally Posted by SCOTI

Yes.

Easy for you to do.
Easy for me too.
But the other 98 out of a hundred will be stopped dead in their tanks and not bother. They’ll look for an easier solution.

[SCOTI]

Originally Posted by geezer#99

Easy for you to do.
Easy for me too.
But the other 98 out of a hundred will be stopped dead in their tanks and not bother. They’ll look for an easier solution.

Well, I didn't know how to do it the first time & you prob didn't either. I learned how by just getting my hands dirty & doing it. There wasn't even an internet to resort to.

One won't learn much (as much?) w/o putting in the effort & trying.

[mongocanfly]

("One won't learn much (as much?) w/o putting in the effort & trying.")
So true

[vintage_mpg]

OK - so I swung by the parts store this afternoon...and the replacement drum still hasn't arrived. Apparently things are a bit backed up and behind, but he assured me it would be here by midweek. That's fine - I'll likely not need it. Just want to put my eyes on it.

[vintage_mpg]

Originally Posted by mongocanfly

("One won't learn much (as much?) w/o putting in the effort & trying.")
So true

So there's a salvage yard within a mile of my house; I'll swing by there tomorrow, hopefully, to take a peek at some trucks to see if they might have a complete rear-end setup with the smaller brakes.

I have a few questions, though....

1) This rear end is a 12-bolt with a Spartan locker. I'm not sure how that works; anyone with any experience there? I looked up several youtube viddies on how to remove axles from a 10-bolt, but haven't looked up the 12-bolt yet. Are they the same? Even with the Spartan locker?

2) Will swapping from the 2 3/4" brakes to the 2" rear brakes impact any part of the rear axle fitment? Meaning.....when I remove 3/4' of the brake width (swapping from the 2 3/4" wide shoes to the 2" wide shoes), does that play into the length of the axles, brake drum, etc? Or will it all come together just fine? Or will the axles now be 3/4" strong on the ends? I'm guessing it will be fine...but this is all new for me, so I'm trying to think ahead

3) Are the rear brakes the same (meaning 2" brakes) for a 10-bolt as they are for a 12-bolt? I have a feeling I might only find the 2" brakes on 10-bolt rear ends, and the 12-bolts will all have the 2 3/4" shoes. Just an assumption on my part, but being that the 2 3/4" are heavier duty brakes, seems they'd all be found on 12-bolts....but maybe that's not true at all.

I'm going to go poke around in the salvage yard/boneyard to see what I might discover. They usually have a decent selection of old stuff....but it's getting thinner and thinner each time I go looking for older stuff. I just want to put eyes on a 2" rear brake setup, hopefully from 12-bolt rear-end. Maybe I can buy backing plates and springs/other hardware from the boneyeard, then get some new shoes and drums to complete the swap.

Thanks for all the positive input! I've never busted into my own rear diff, so this is uncharted territory for me. I wouldn't even consider it if it weren't for your comments and encouraging remarks - so THANK YOU!