Rear end swap questions

[Fine59]

I have searched through everything I could find, but haven't come across anything detailing swapping in a 73-87 rear end into a 66 suburban, I know the 73-87 rears are 1 1/2 inch wider than the stock 66,what I'm trying to find out is if I do this swap can I run a 15x8 rally wheel and have clearance in the wheel wells? Anyone ever do this?

I've swapped the front suspension from my 87 parts truck and it fit like a glove, just trying to figure out how the rear will fit in one of these suburbans, I'd rather use what I have instead of spending $ on new axels and brake drums

[PGSigns]

Do you need a 12 bolt to go in it or are you trying to get to 5 lug? Updating a trailing arm 12 bolt may be easier than adding the mounts and swapping to an after market track bar. Tell us more about the plans for the truck. I am not that far from you and can help with questions.
Jimmy

[Fine59]

Like I said I have swapped in the front suspension from the 87 donor truck, have 3 inch drop spindles going on it, going small block crate motor,700r4, plan on doing a lot of driving, east to west coast kinda driving, so that's kinda what made me want to do the swap, off the shelf parts while road tripping takes a lot of the strain off these trips,
My donor truck has a 12 bolt in it, five lug, heavy duty brakes,just figured brake parts and such would be more plentiful with the 87, welding on the trailing arm brackets are not a problem, just want to make sure I have clearance in the wheel wells, 15x8 rally's and lowered 4in or more, thanks Fred

[Fine59]

Like I said I have swapped in the front suspension from the 87 donor truck, have 3 inch drop spindles going on it, going small block crate motor,700r4, plan on doing a lot of driving, east to west coast kinda driving, so that's kinda what made me want to do the swap, off the shelf parts while road tripping takes a lot of the strain off these trips,
My donor truck has a 12 bolt in it, five lug, heavy duty brakes,just figured brake parts and such would be more plentiful with the 87, welding on the trailing arm brackets are not a problem, just want to make sure I have clearance in the wheel wells, 15x8 rally's and lowered 4in or more, thanks Fred

[PGSigns]

All the brake parts are readily available as I just got everything for the 66 yesterday. You are not gaining ease of availability with the later 12 bolt due to the internal parts are the same on your stock 12 bolt as the are on the later one. The bigger brakes (2 3/4" shoes) can go on your stock housing using C10 drums for 5 lug or K10 drums for 6 lug. I have the 6 lug K10 stuff for my Suburban. How well the wheels work will depend on back spacing and tire size. Doing the axle swap to go to 5 lug will give you more room in the back with the limited space you have with the suburban. You will also need a long track bar that goes to the trailing arm with the later housing not having the mount tab on it. If you shop around for just the axles and subtract the price of the axle perches and the track bar The cost is not to bad. On the front with the 3" spindles your wheels may not clear the lower control arm. I have 15X8 rally's on my 66 with 4" back spacing and had to do a good bit of grinding on my lower control arms to keep them off the wheel. You may find with the 3" the lower ball joint hits the wheel.
Jimmy

[Fine59]

Originally Posted by PGSigns

All the brake parts are readily available as I just got everything for the 66 yesterday. You are not gaining ease of availability with the later 12 bolt due to the internal parts are the same on your stock 12 bolt as the are on the later one. The bigger brakes (2 3/4" shoes) can go on your stock housing using C10 drums for 5 lug or K10 drums for 6 lug. I have the 6 lug K10 stuff for my Suburban. How well the wheels work will depend on back spacing and tire size. Doing the axle swap to go to 5 lug will give you more room in the back with the limited space you have with the suburban. You will also need a long track bar that goes to the trailing arm with the later housing not having the mount tab on it. If you shop around for just the axles and subtract the price of the axle perches and the track bar The cost is not to bad. On the front with the 3" spindles your wheels may not clear the lower control arm. I have 15X8 rally's on my 66 with 4" back spacing and had to do a good bit of grinding on my lower control arms to keep them off the wheel. You may find with the 3" the lower ball joint hits the wheel.
Jimmy

Thanks for that info, I had no idea on the brakes, so getting the 5 lug replacement axles might just be the way to go for me, I got the Beltech spindles from summit, I hope there wasn't a disclaimer they wouldn't fit a 15 inch wheel...man I gotta start paying attention to the details.... Fred

Ps if your in need of a 6 lug rally wheel I have 4 that are collecting dust

[PGSigns]

They more than likely don't have a note on wheels. With as many combo's as there are out there its hard to cover them all. Asking questions here in the main truck side when it comes tot he generic stuff like wheels and brakes before ordering parts can be very informative. Some of have been at these trucks a long time and have had the opportunity to go OH CRAP a couple of times and had to rethink the plan. I have 15X8 on the front of the 66 and went to 15X7 for the suburban to get more a arm room and to be able to run a smaller tire on the front. Had some rubbing issues with the first set of tires that was on it and went to a 235 75 on the second set. Wanted to do a 225 but thats a little narrow for an 8" wheel.
Jimmy

[VictoriaHardware]

I have a '66 Sub with Bell Tech drop spindles on the '66 a-arms and GM 15x8 wheels (3 3/4" offset). I had to grind about 1/4" off the a-arm lower edge around the ball joint. Besides that, it all works together well.

The wheels fit in the rear wheel wells OK. I have P275 tires and are near max when allowing for body roll. If your axle is an extra 1 1/2" wider, you will be chewing up the outer sidewall with the fender lip. If you run skinny tires &/or hack the lips you can possibly make it work.

[Fine59]

Originally Posted by VictoriaHardware

I have a '66 Sub with Bell Tech drop spindles on the '66 a-arms and GM 15x8 wheels (3 3/4" offset). I had to grind about 1/4" off the a-arm lower edge around the ball joint. Besides that, it all works together well.

The wheels fit in the rear wheel wells OK. I have P275 tires and are near max when allowing for body roll. If your axle is an extra 1 1/2" wider, you will be chewing up the outer sidewall with the fender lip. If you run skinny tires &/or hack the lips you can possibly make it work.

Thank you sir for continuing my education on these cool old trucks, Fred

[PGSigns]

Is that you on Craigslist looking for a 71or 72 5 lug rear? If so it is also wider than the one in your truck. It is the same as the 73 and up. It was made wider when the disc brakes were added.
Jimmy

[Fine59]

Originally Posted by PGSigns

Is that you on Craigslist looking for a 71or 72 5 lug rear? If so it is also wider than the one in your truck. It is the same as the 73 and up. It was made wider when the disc brakes were added.
Jimmy

That's me.... i was of the understanding the were 1 1/2 inch wider
But still a bolt in being they were still coil spring in 71-72....

[PGSigns]

They will bolt in and are hard to find. It will be wider and may force you into a new set of wheels. I have not seen one in a while in our area. You may luck out and someone has one stashed.
Jimmy

[Fine59]

Originally Posted by PGSigns

They will bolt in and are hard to find. It will be wider and may force you into a new set of wheels. I have not seen one in a while in our area. You may luck out and someone has one stashed.
Jimmy

It's still pretty surprising what's out here in Chesapeake, I figured I'd give it a shot, between here and the OBX there are a lot things stuck in people's back yards, I bought a 31 Plymouth a few years ago that had been stashed in a pole barn back in the 70s, still had the original canvas top in the roof, was gonna hot rod it but ended up selling it to a guy from the Plymouth owners society of America....

[63burban]

The plus with 1980s rear axles is a better gear ratio. I am using a 1991 Suburban rear axle with 3:42 gear and limited slip and will order wheels accordingly. I will also be on the highway a lot with this one. TBI 350 and 700r4 should run down the road great and get 18 mpg

[Fine59]

I broke down and bought the replacement axles for it...less work fabbing and measuring, got all the 87 front suspension stuff bolted up, going to pull the rear end this week and get started on that...700r4 is at the shop getting gone thru and have a bright shiney new motor in a crate waiting to go in...only thing worrying me is rebuilding my slider window frames, got the track material and had a friend make me a 3/8 buck out of plate steel...going to put some heat to the track and see if I can get a decent bend without it crimping to bad....dolly and hammer are standing by....