[Derek]

ok i have a few questions
my truck has 10 bolt 8.5" front and rear correct?
other than opening the dif up and counting teeth how can i tell what gears i have?
and lastly what should i be looking for pricing to install a locker and gears, if i buy the parts myself?

 

[onyx]

the RPO codes in the glovebox

umm.. actually i dunno if an 85 has them in there..... :crazy:

 

[Nicholas]

85s might have them...i checked in an 87 or 88 once, and it had the codes plus what they actually were...like G80 - Eaton gov loc.

 

[onyx]

85s might have them...i checked in an 87 or 88 once, and it had the codes plus what they actually were...like G80 - Eaton gov loc.

nice...

 

[Derek]

ill look
thanks

 

[onyx]

let us know how it goes.

 

[jebx]

All the older ones are like gu4, gu5, that I have seen. I had an '84 with a 2.73, uggh. There also should be a tag on the differential that has the gearing information also.

GU2 AXLE REAR,2.73 RATIO
GU4 AXLE REAR,3.08 RATIO
GU5 AXLE REAR,3.23 RATIO
GU6 AXLE REAR,3.42 RATIO

 

[Rednecked_4x4]

usually inside the glovebox.. like they said.. but all mine havent had codes, it always says 3.73 or 4.10 for me.

 

[Derek]

i just checked my glove box and it says 3.08
that seems kinda fishy to me tho cause my 305 has no problems spinning my 33's and i dont think 3.08's would allow me to do that?
any input?

 

[Nicholas]

That is very fishy...i have 3.08s and 33s, and on dry pavement i cannot get my TB 350 to turn them over...i used to have to powerbrake a lil with my top off to break traction on my 31s...Id run a few more RPO codes to see if its the right sticker for you truck (ive wondered on mine before cuz theres a lot of things that didn't come out right). Check the tags on the diff to see if theres anything on there...

 

[Derek]

i cant say i have ever noticed a tag on either of my diffs
where are these tags?

 

[Derek]

ok i just went and looked and i see no tags anywhere on either of my dif's
is there anyway else to check?

as for the glove box being wrong i find it hard to believe because everything else is correct, unless they were swapped before i bought it

also can anyone answer this question

and lastly what should i be looking for pricing to install a locker and gears, if i buy the parts myself?

 

[Rednecked_4x4]

3.08s are fucking worthless blowass :wank:

when you say your 305 has no problems spinning them, spining them where?

I got a buddy with an '85 k5 blazer with a 305, 3.73 gears, 4" lift and 33's and he can spin his on gravel thats about it.

Do you know the previous owner? perhaps they or someone they know switched ratios on them. That is very common. Yet another friends '86 k1500 with a 4" lift and 33's his glove box said 3.42 but he has 3.73. :read:

 

[Derek]

for the most part i can get them to break loose any time i take a corner from stop and sometimes just getting on it leaving a stop they will break loose

i dont know the previous owner, but i am guessing they must have been switched
any way to tell with out opening them up?
they could probably love new oil anyway so ill probably just do that

 

[Rednecked_4x4]

i'd just count.. that way you know for sure and aint guessing. I'm guna say that if you can spin them you probably have 3.73..

what were your RPMs like at 65 before the 33's?

 

[Derek]

wish i knew, no tach :bawl:

 

[Nicholas]

when i said i couldn't spin them, it was from a dead stop goin straight...even if i have the wheels turned some and get on it, itll break loose...hell, i got on it hard around a big turn through an intersection last night and it shifted to the top of first and smoked one of them...gotta love how shitty the gov lock is and how it won't hold up to 31s...

 

[Rednecked_4x4]

"when you say your 305 has no problems spinning them, spining them where?"

i realize that was a dumb question.... where i meant like in the mud, on pavement, on gravel...but im probably the only backwoods idiot thats surrounded by gravel roads! :crazy:

 

[Derek]

ha its cool dude im from the back wood we have dirt roads in town still