rearend ?'s

[The Beast]

ok i have a 78 c10 short wide. i belive i have 2.73 gears but i dunno i want to have a locker put in by a shop and was looking at a gear type rather the clutch type. anyways im having trouble figuring out what rear end i have (10 bolt, 12, or 14) as well as axel spline count. i just want to order the locker with maybe some 3.73 gears and get a shop to install it for me. or if anyone in the seattle, washington area that can recomend a shop to do the work for me. i work in a performance shop but i dont feel like doing the work on my own truck right now lol.

[Captkaos]

IF it is original, it will have a 12bolt axle in it with 28 spline count.

[The Beast]

great thanks for the help, then i can look on the option card on the glove box to see what thrice of alphanumerical for the rear end gears?

[Blazin]

It might not be on the option card. SOme of them just say standard rear end ratio. As far as 10, 12 or 14 bolt. Duck under the back of the truck, & count the bolts.

[The Beast]

It might not be on the option card. SOme of them just say standard rear end ratio. As far as 10, 12 or 14 bolt. Duck under the back of the truck, & count the bolts.

i didn't think it was that simple for findout out what diff i got lol. and what about the old trick of jacking up the back marking locations and turning a axel and count the revolutions until they remeet?

[werewolfx13]

It works, its not precise, but it gets you close enough to estimate.

[SUX2BU99]

Somewhere around Seattle is Randy's Ring and Pinion. One of the best well known shops for rear end parts in the aftermarket. Do a web search, I'm sure they'll pop up.

[Captkaos]

http://www.randysringandpinion.com  I highly recommend them...  I get everything from them and never got anything sent that was incorrect.

[The Beast]

cool thanks for the help everyone.

[Fordeatinz71]

man, i'm ducking in late here, but if it's a standard LD 1/2 ton, it should have a good 'ol 10-bolt in it.  and yea, most likely with 2.73 or 2.76 gears.  find your gearing code and get it on here and i'll help ya figure out exactly what it is...

[1976Scottsdale]

Yeah, being a 78, it would have a factory 12 bolt and most likely either a 2.73/76 or 3.07 axle ratio. 

[The Beast]

ya i ran the rpo codes months ago and i thin it came up as 2.73's, and its a 12 bolt. so in a few months its going to the shop for new axels, locker, and 3.73's

[VileZambonie]

I think late 81 was when they started using the 10 bolt

[Captkaos]

Yep, started in mid 81 and was phased out by 1982.

[Fordeatinz71]

yea, i realized after doing some reading that the 12-bolt should be in his truck...i was gonna edit my post but ya'll replied beforehand.  anyway, the 10-bolt was used for longer than a year i think.  i had a '79 that i KNOW had a 10-bolt (had to rebuild it) and my '83 has 10-bolts at both ends...my '89 also had a 10-bolt rear...so did my '90...