The Stovebolt Site Forums The Shop Area Engine Shop Rear end again

Hi all, Long time no post. Merry Christmas and Happy Holidays to you.
I have always read with interest the numerous discussions on rear gear swaps as I own a 3/4 ton truck. It seems to always come down to finding a later model pumpkin or do a complete rear swap. I seem to recall a recent discussion on this and someone mentioned the type of rearends involved. Do I understand correctly that the Chevy and GMC trucks used different rear ends? Are the Chevy rear gears unavailable but the GMC a different story? My truck has what I believe to be the original Spicer(Dana)60 rear. Some places advertise different ratios for these (Dana 60). Would they fit this earlier model? Any and all opinions and replies appreciated.
Thanks,
Jeff

jmoore,

There are numerous posts on this site if you look under "rear end" or "differential swap" etc. Basically, a '67-'72 automatic w/coil springs in the rear should have a 4.10 but you need to pull the cover to be sure. 4.10 is about as tall as you'll find in a 3rd member rear axle.

see
http://www.stovebolt.com/bboard/cgi-bin//ultimatebb.cgi?ubb=get_topic;f=2;t=012566#000000

&&

http://www.stovebolt.com/bboard/cgi-bin//ultimatebb.cgi?ubb=get_topic;f=2;t=011805;p=1#000013

jmoore:

Try JC on this site. He seems to be very knowledgable about the 3/4 rearends and the gear swaps.

jmoore,
Looks like you're questions were misunderstood.
Here is a hemmings article on the Dana 60 that is pretty informative and tells what vehicles they were found in.

http://www.hemmings.com/mus/stories/2006/04/01/hmn_feature27.html

Also, here is a source for Dana 60 ring and pinion gears.

http://www.markwilliams.com/detail.aspx?ID=1481

Thanks everyone.
Yes Ghostrider I believe my question may have been misinterpreted. I think I have read every post on rearends, gear swaps, etc. on this site for over three years that I have been a member. Maybe I missed it. I know most members here are Chevy owners so I believe that their situation may be different than mine(GMC). I suppose I will contact gear vendors with some #s and see if the gears they offer will fit. I had just hoped maybe someone here with a GMC might know.
Thanks again,
Jeff

Is the cover on the rear end round or sorta hexagonal? How many bolts on the cover? I had a spicer 45 in my 1/2 ton. Years ago when I was looking I was told there was only 3.15:1 gears available and they were a bit pricey. I had 3.08 gears so that didn't give me much of an advantage. Identify what axle you have and then go to a reputable rear end shop. They will be able to tell you if there are any parts still available. You are right... you do have a shot because it is a GMC!

Hey BBSDaddy,
Thanks fer the response. Yea its not the round one, its kinda hexagonal, with a drain plug on right just below center. It looks like the one in Ghosts first link so I reckon its a Dana/spicer, I just wanted confirmation. The #s I could find on it are a tag that says 41/9(ratio), a stamp "60" on lower right, the #s C30255 on upper housing and 257A 2236 1 on axle tube. It is good to know this may not be so difficult after all as all this time I thought I was in the same boat as Chevy owners. I hope this info can help someone else out too.
Thanks again,
Jeff