1971 GMC with manual 4 spd-what is the stock ratio???
 

So, i don't have any ratio listed on my glove box option sheet. What do the experts say was the std axle ratio for a truck that came with a 350 and a 4 spd manual. The 4 spd seems to have a very low granny gear in 1st....
Thanks for the future opinions.

Re: 1971 GMC with manual 4 spd-what is the stock ratio???
 

Is the truck a half ton 3/4 ton or 1 ton? Also original motor and trans?

Re: 1971 GMC with manual 4 spd-what is the stock ratio???
 

Here ya go.. I am assuming its a GMC 910 but I've added the GMC 920 specs as well.

Re: 1971 GMC with manual 4 spd-what is the stock ratio???
 

It is a 1/2 ton 1971 GMC. I was hoping for the 3.07!! I dont want to pull the cover off as it is very original and no leaks...

Re: 1971 GMC with manual 4 spd-what is the stock ratio???
 

That would suggest the fluid was all original. And I'm pretty sure that it could use a change, a fresh gasket as well as a pinion seal...

Rear diffs are typically abused in the sense they get zero maintenance until they are broke or worn out.

Re: 1971 GMC with manual 4 spd-what is the stock ratio???
 

Looking at the posted chart and if there is no optional ratio on the spid then you should have 3:07..

Re: 1971 GMC with manual 4 spd-what is the stock ratio???
 

Second owner of a 71 GMC with 465 4 speed. SWB and it is a 3:07, now a 355 sbc still the 4 spd and 3:07

LILREDGMC