69 chevy tanny ratios?

[jwspin]

hi im new to the board, happy to find this out there. i have a 69 chevy c10 pickup that my grandfather bought new and has since been passed down. it is a typical work truck and will need a bit of help but im up for the task. i have a few questions.
it is a 292 with a 4 on the floor, what transmission code is it, and what are the ratios?
it also has an 8 lug rear end, is that stock, what final drive ratio is in the rear end?
lastly what is the curb weight of the truck?

thanks
-jared

[jwspin]

anybody?

[Longhorn Man]

if it is a c-10, then that rear was swapped in.
If the rear is 67 - 72, then 4.57 is common, and 4.10 being a tick less common. That's about as good as it gets.
Can't help you on the tranny ratios.
Do you have any photos of the odd parts of the truck?
Maybe a pic of the SPID?
Whats the first 1/2 of the VIN (full vin is cool too, but some ppl are scared of truck ID theft)
photos of the center part of the rear axle would help tons too

[Ace in the hole]

like Longhorn said about the rear end, c10= someone swapped in a 3/4 t rear end. If it's a c20 though, you have a 3/4 ton truck. As for the trans, if it's original it could be an sm465. They have a really low granny gear. More info on them here- http://novak-adapt.com/knowledge/sm465.htm
It really depends on what you have, if someone swapped in a different rear, you could easily have a different trans too.

[special-K]

Final drive = 1:1 on all transmissions.Then,some have overdrive in later years,but that`s not final drive,that`s beyond final drive.

[WorkinLonghorn]

I thought "final drive ratio" usually meant the rear end as in

Definition: The reduction ratio, found in the gearset of a drivetrain, that is furthest removed from the engine. Typically, the differential ratio

http://autorepair.about.com/library/...bldef-072a.htm


Anyway it could be the SM465 referenced above or it could be a NP435 which has 4.56-1 low,2.28 2nd,1.31 3d,and of course 1-1 4th gear.

[special-K]

When talking about a truck,yes.When talking transmissions the final drive is top gear.I didn`t read all of it,I guess.The rear ratio is prolly a 3.73,but you`d have to check to be sure.

[jwspin]

thanks for all the info so far. i remember my dad telling me when i was a kid that his father ordered the truck custom tailored to how he wanted it. my dad passed away when i was pretty young so now im just trying to figure out a bit more about the truck, unfortunatly the truck is at my mothers house in NY and im in NH right now. when i get back to visit ill look over the truck and see if i can get some numbers off of the tranny and the rear end, maybe some pics. i thought it was kind of weird to have 6 lugs up front and 8 in the rear. i wouldnt put it past my father or grandfather to swap in a 3/4 ton rear end to handle the work load that they were carrying. my dad used to tow a skidsteer and a tractor with a 4 cyl toyota....

thanks so far everyone

-jared

[69GMCLonghorn]

I had a '69 Chevy 4-speed that was an SM465. Now I have a '69 GMC 4-speed with an NP435. The first gears are 6.90:1. The 4.56 first gear came on the later NP435's, not in this vintage truck. Unless of course the tranny was swapped out. The rear end will not be a 3.73. It will most likely be a 4:10, unless something nonstandard was swapped in it. Get the speedo calibrated, get a good accurate tach (if it doesn't have one already), and take it up to 70. If you're in the neighborhood of 3000 RPM, you're running a 4.10 rear end.