1969 gmc

[dbaillargeon]

To all,

I wanted to start by saying how much I appreciate all of the people who have provided priceless information on the this website. I have been able to remedy or fix most of the challenges during my daily driver restoration.

I have however found a need to do some work on the rear end of the my 1969 GMC C30 Longhorn. The motor is really strong but first gear is useless (granny gear) and I would like to give her a little more speed going down the road. My question is what is the best upgrades/updates etc. The rear end is a 14 bolt rear end and I have searched for a part number to identify it with no luck. I have even pulled the cover and searched the interior of the housing.

Does it make sense to re-gear it or change the entire rear end?

[LockDoc]

Originally Posted by dbaillargeon

To all,

I wanted to start by saying how much I appreciate all of the people who have provided priceless information on the this website. I have been able to remedy or fix most of the challenges during my daily driver restoration.

I have however found a need to do some work on the rear end of the my 1969 GMC C30 Longhorn. The motor is really strong but first gear is useless (granny gear) and I would like to give her a little more speed going down the road. My question is what is the best upgrades/updates etc. The rear end is a 14 bolt rear end and I have searched for a part number to identify it with no luck. I have even pulled the cover and searched the interior of the housing.

Does it make sense to re-gear it or change the entire rear end?

There are basically 3 ways you can go. Change the rear gears, (this thread tells how to decipher the code markings on the ring gear):

http://67-72chevytrucks.com/vboard/s...d.php?t=617255

Change the transmission to a 5 speed overdrive. (the following two threads tell how to do that):

http://67-72chevytrucks.com/vboard/s...d.php?t=313954

http://67-72chevytrucks.com/vboard/s...d.php?t=673588

And the last would be the Gear Vendors Overdrive Unit.

http://67-72chevytrucks.com/vboard/s...d.php?t=209282

http://67-72chevytrucks.com/vboard/s...d.php?t=363262

The pictures are screwed up on the last one but still some good info.

LockDoc

[special-K]

The only thing I'll add is if the ratio isn't 4.10 you can swap the gears really easily. 4.10s are the best you can do for road gears in that rear. Look at taller tires as well.