70 suburban rear end swap question

[67Mach1]

I am about to purchase a 1970 suburban. The front brakes have been changed to five lug disc and the rear are still six lug drum.

Would like to change to five lug? what are my options using a donor rear end or I have heard about only swaping the shafts and drums. Is this possible?

Also, Heard that the 71-72 rear ends are of a different width than the earlier ones too, is this a myth or reality?

thanks,

[cstanley]

i've heard late '70s early '80s cadillac rear ends might be a good option. they have the disc brakes and 5 lug truck pattern. don't know about the width, though.

[Hart_Rod]

You might want to crack the rearend cover and see what gear ratio you have and what shape the gears are in. If in good shape and correct ratio, I would just swap axles and drums (about a 1 hour swap). If not in good shape, start searching for a donor rearend. I got lucky and PO had the entire rearend rebuilt with new gears and and a new posi ($1800!!!). So I just bought an Early Classic's axle conversion kit, instead of getting another rearend.

Rob

[NateObee]

Originally Posted by 67Mach1

Also, Heard that the 71-72 rear ends are of a different width than the earlier ones too, is this a myth or reality?

I got a Rear end off of a '69 sub and put it on my '72 Blazer. the 69 is shorter than my 72 was. course that's a model change too, but the numbers on the tube are the same. the ratio is the same. i had to get a special asymetricial u joint (in stock at Napa), so it can't be that uncommon.

Nate

[Green Machine]

My 1970 truck rear end is the same width as a 71-72, some may have the wider rear and some may be the 69 and older width. If you have the wider one, a simple axle and drum swap will do it, else you can have the old axles redrilled, or swap entire rear end.

[Longhorn Man]

Green got it right... if it's an early 70, narrow, late 70, wide axle.

[67Mach1]

Thanks I ahve access to a 72 rear end that might be in good shape... Truck was rolled over on roof and back down again. If it will firt I might jsut swap axels and drums.

thanks agaain, I had always thoughtt he wider rear axel thing was a hoax.

thomas

[67Mach1]

Originally Posted by Longhorn Man

Green got it right... if it's an early 70, narrow, late 70, wide axle.

Longhorn Man, how can I tell if it is early or late?

Measure the rear end? or is there a date code associated with the vin?

Thomas

[Longhorn Man]

To my knowledge, no one has figured dates to vin yet, I doubt it can even be done acuratly. If you have the sticker in the door jamb, you can guestimate... but the only way you can be certian, is to measure it out.

[70GMCer]

What is the width of the narrow and wider rears?

[Longhorn Man]

56 inches
57 1/2 inches

[70GMCer]

thank you

[67Mach1]

Originally Posted by Longhorn Man

56 inches
57 1/2 inches

LHM. Measuring from where to where?

Is tere a standard way to measure them? Inside of backplates, front of drum to front of drum?

Any help would be apppreciated?

Thanks.