[chiphead]

What is the drum to drum measurement for a '67 A body rearend? I measured 60" drum to drum on my LeMans. Is this right for factory R/E?

[Bill Eveland]

That should be correct, the earlier rearends are what you have and the later - like the one in my 68 GTO are over 62" wide .
I know you have been looking for rearends, have you found any from a Dodge b-body cars maybe on ebay? They are about 59 1/4" wide and have the smaller 4 1/2" bolt pattern.
66-70 9 3/4" ( Dana 60) and 62-70 8 3/4" . Either should be strong enough for what you need.

['ol Pinion head]

No, 60" drum to drum is not correct for '67, that is the '64-mid '66 8.2 rearend width. All '67-72's bolt-in axle rears were 55.25" backing plate to backing plate & this will translate to over 61" with drums on.

'64 (one year housing) & '65-67 Chevelle 10 bolts & '65-67 Chevelle 12 bolts were narrow as well. By the '67 Chevelle 12 bolt being narrower, folks assume that '67 BOP offerings were narrow as well, not so.

[chiphead]

Well, that would explain why the axles from my '72 parts car are longer. So I guess my rear has been swapped? In a previous life, my car was rear ended pretty badly. I guess the rear axle was trashed in the wreck.

If I was to have a rear built for my car, what width would be ideal? My tires are already too close to the outer wheelhousings.

thanks

robertg

[Bill Eveland]

What I meant to say is that you had the correct width earlier rear, but not for a 67, like oph stated. Pretty sure on the width of the later rear, it measured more like 62.5"

[Pontiac signman]

Guys,

I have a 58" backing to backing in my 67 thats dated for 70. I'm picking up 12-bolt thats 54.5" back to back.

Just stating what is there. Don't know if the 58" is Pontiac or BOP, but definetly 8.2 with smilies on sides.

[Shadowjack]

This just slays me. No WONDER the width dimension is all over the map! 60", 61", 62.5", jeez! OPH, am I wrong in stating that there were only TWO widths from the factory, whatever those may be? Maybe we'd all better get new tape measures! And just for fun, this is my '69 8.2", measured from the opposite point...

[Bill Eveland]

What good does that measurement do?
Most have there backing plates already bolted up, so unless you know the offset of the brakes and differance from axle flange to housing flange.
The only accurate one is to measure wheel mounting surface to surface. Mine was measured with 2 stright edges against the wheel mounting surfaces . That was out of my 70 GTo that I put in my 68- same width as we know. I built all my kitchen cabinets with that tape measure ,i'm pretty sure it's accurate.
Don't we go thru this every time someone brings up rear end width?

[chiphead]

Guys,

After seeing the differances in measurements, I went back and re-measured my R/E. Being more careful, from wheel mounting surf to wheel mounting surf, I get 60.875". Basically 61".

The point is if I want to move the tires in 1/2" on each side, do I need a 60" R/E built?

thanks

robertg

['ol Pinion head]

Robert,
Until you can decide on what wheel & tire combo you want to run under your '67, the rearend width question is moot. Have built more than my share of 12 bolts & HD 8.5's to fit in '64-65's & '66-67's. Either will fit. Which wheel tire combo one picks (or has to run) will determine if the tire is jambed up up against the wheel well trim, or is getting close to the frame & shock mounts.

['ol Pinion head]

Shadowjack,
I agree with you. The one that got me was 58" backing plate to backing plate.

Here are the r/e widths that stock '64-72 GM A-body r/e housings came with. Currently have in stock over 140 housings, have been answering this exact question for years, & can perfectly read a tape meaure.

Backing plate to backing, ie, flange to flange:

-narrow BOP 8.2: 54.25"
(will pull out & measure an early Chevelle 12 bolt later today, but it will be real close to the early '66 GTO housing I just measured)

-"wide" Pontiac 8.2 10bolt,
-type "O" Olds
-'68-72 12 bolt,
-'68-72 10 bolt chevelle,
-early 8.5 A-body rear: 55.25"

-'73-77 A-body: 56.25" - 56.375"
(will not bolt up in a '64-72 A-body as upper cast perchs have different spread)

Measuring several 8.5 A-bodys & '68-72 Chevelle 12 bolts with axles in both, just came up with 61 1/8", from machinined axle surface to machined axle surface. On the above 8.5 A-body rears with oem Chevelle drums slid on (.110" thick) one will measure 61.335" from where wheel mounts to where wheel mounts. '68-72 12 bolt Chevelle is also going to be real close to same dimension.

Hope this helps.

[chiphead]

Right now I've got 15x8 centerlines with 4" of backspace. The 235/70-15s are rubbing the outer wheelhousings. Maybe using shorter tires will help clearance. I'm thinking two 15x8 by 4.5" rims and street slicks will work perfect with a 60" rear when racing. Then I can run my centerlines and street tires on the street without rubbing.

thoughts?

[Junkyard Dog]

You need another inch to inch and a half of backspace . . . i.e., 5 to 5.5 inches.

['ol Pinion head]

Robert, what are exact width are your centerlines?

The "15x8" centerlines I've owned, going to date myself here, were Autodrags & Champ 500's. They were actually 15 x 8.5's (inside the bead) & had positive offset, making these wheels stick out on back of 2nd Gen T/A. Same wheels on a '67 GT0, I'd bet are going to stick out, just like where you are at right now. 4" backspacing, going to equate to somewhere around 1-1.25" positive offset.

Several years ago I was able to fit 275-60R15's on 15x8.5's under a '64 Chevelle, it was real tight. On small slicks & spray, same car ran 10.40's, & the r/e was built-up 8.5 A-body (61.335" wide). The wheel offset was critical with both big street tires & his slicks. If any comfort, a '64-65 Chevelle wheelhouse is lot smaller than a '66-67 GTO. Putting down enough serious torque where you think you need a Dana60, going to need as big a tire as you can fit in the wheelwell. Prob best to find out who has fitted the largest sticky tire/wheel combo under a '66or 67, then find out what wheel offset worked best for them, then can arrow down what r/e width is best.

Going to make a phonecall. Used to own a '67 GTO that had a '71 12bolt in it & slicks. Still have the rear wheel opening moldings which were trimmed to 1/4". Buddy I bought it off of kept the wheels & slicks.

[chiphead]

Honestly, I dont know the 'exact' measurements of those Pacer-brand centerlines. A local tire shop fitted the wheels/tires while I was at work. The tires are too tall, but I can always wear them out. The rims I like.

OK, I've got a confession. My car was rear-ended in a past life. The sheetmetal dimensions are crazy where somebody reshaped around the wheelhousings. I've got more clearance on the driver's than passanger's side. I've done some body work and cut/rewelded the wheelhousings to compensate. Hope I can help this with a tire/wheel/axle combo.

OPH- Was that you I emailed about a set of 8.2 axles?

thanks!

[Old Man Taylor]

CenterLine made the Autodrags in at least two offsets. I have the 15x8.5 with a 4 15/16 backspace. It is tight, but it centers the tire nicely in the back of my '64 GTO. The rear end is the stock '64 width, but it is from a '66 Chevelle. The tire I have been using is the M&H DOT tire, 275x60-15.

[Junkyard Dog]

OMT, your 428 rebuild story on that page is hilarious . . .

[Shadowjack]

The point of showing that dimension is that there are no other parts to get in the way of the measurement, i.e. the stickout of the axle flange, or the thickness of the brake drum, or anything. Just the bare housing, which should be either a wide or a narrow. This is a wide. I admit it's not useful in the field, but it is an absolute figure for comparison.
It's a moot point about the axle stickout, because as far as I ever heard, all 9.5" GM rear drums will interchange, leading me to suspect that dimension never changes.