what gearing in 74 k5 12 bolt

[az88k5]

I have a twelve bolt out of a 74 k5. I need to know what the gear ratio was in this stock. does any one know? Thanks any help much appreciated

#'s are as follows 11 2 73 Dana 18515 A3D87 41-11
Are these 3.73's or what

 

[Muddytazz]

pop the cover and either count the teeth or read the numbers on the ring gear

 

[az88k5]

The pinion fell in and I can't turn the ring gear or I would, and its not worth pulling the axles and carrier. thanks for the info though

 

[84PolarBear]

It should be 3.73

 

[Muddytazz]

not necessarily....i've seen 3.08's, 3.73's and 4.10's all being stock for that yr

 

[pauly383]

Bit of trivia , 3.08's in a 12 bolt are actually 3.07 and a bunck of decimal places

 

[Muddytazz]

paul, on my old 1/2ton stuff (D44/12b) the numbers came out to 3.07 on my 44 and 3.08 on the 12b

 

[imiceman44]

I have a twelve bolt out of a 74 k5. I need to know what the gear ratio was in this stock. does any one know? Thanks any help much appreciated

If it was auto it should be 3.08
If it was a manual they had the choice 3.73 and 3.08
Although you could always have custom gearing, but standard for 74 was those numbers.

 

[Cmoe]

My 74 came with 4:10's.... so you'll need to pull the cover and check manually....

 

[imiceman44]

My 74 came with 4:10's.... so you'll need to pull the cover and check manually....

Do you know for a fact it was stock?
Was it with a tow package?
What engine did it have? the 400 SBC came with higher gears too.

 

[Cmoe]

1974 K-5, Trailer Special, 350/350/203... and yes it's on the RPO as 4:10's....

 

[imiceman44]

1974 K-5, Trailer Special, 350/350/203... and yes it's on the RPO as 4:10's....

Yeah I forgot about special editions like trailer, HD, tow package, those came with different gearing, but they were noted, badged as such.
Most production lines were the same as described above.
I had lots of spec sheets from the dealers in the mid 70's that is why I know a little bit about this.
They had a little more info than the sales broshures.

 

[nau81blazer]

The pinion fell in and I can't turn the ring gear or I would, and its not worth pulling the axles and carrier. thanks for the info though

Did you happen to fix this yet? I really need some 3.73 or lower that I can just bolt in...Thanks.

Adam

 

[az88k5]

Did you happen to fix this yet? I really need some 3.73 or lower that I can just bolt in...Thanks.

Adam

No I'm not going to fix it, I don't have the yoke for the pinion.

 

[az88k5]

heres the #'s off the ring gear

11 2 73 Dana 18515 A3D87 41-11 389

Are these 3.73's or what????

 

[1BEATK5]

41-11 means 3.73 41 ring gear teeth divided by 11 pinion tetth gets the answer

 

[imiceman44]

11 2 73 Dana 18515 A3D87 41-11 389

Are these 3.73's or what????

Yep 3.73 and this is the original for your 74, built november 73.

 

[Gorillajeep]

What gears did the 400 SBC have? You brought it up. . . .
James

 

[imiceman44]

What gears did the 400 SBC have? You brought it up. . . .
James

Well supposedly 3.73 or optionnal 4.10 no 3.08.

As for my "original for you 74" I meant gears said 11-73 so late 73 for a year model 74 so most probably still the original gears.