1966 K10 Axle Gear Ratio

[AlaskaK10]

Hi Everyone

Got a question ....On a 1966 K10 what were the factory gear ratio? I think mine are 4;10. If so am thinking in todays times a higher gear ratio would be better. So far my plan is to run a 292 with a SM420. For the sake of originality except that I am going to switch to disc brakes and I am not opposed to keeping the closed knuckle front axle but would not rule out going with open knuckle. It probably would be cheaper to find a matching front and rear end out of another truck than say changing gear carriers what say you?

[bsarts]

I think the carrier break is at 4:10 and below so you should be Ok to just regear it. But you probably could find complete running gear from another truck for less money and less work. I'm with you as far vas originality goes though, my K20 has 4:56s in it and I would have kept the axles and regeared it if I didn't have to buy new carriers too. I found front and rear axles out of a 1980 for around 600.00. Haven't put them in yet though...

[rideblue00]

FWIW, just my 2 cents...in the standard 1/2T 2wd axle 3.73 up to 4.10(not sure about 4.56) is one carrier size and 3.42 and less is a different carrier size. I have the 3.73 in my 1/2T still, but have bought the diff carrier to run 3.42. Im sorry I dont know that carrier part number off hand, but some digging from someone with a GM parts manual they should be able to confirm, even with K series.

[Arne]

If you are planning both a different ratio and disc brakes up front, I'd pick up a matched pair of later axles. Axles with disc from say, a mid-80s K10 or ½ ton Suburban should be easily found and affordable.

[AlaskaK10]

Thanks for the suggestions. What would be a good gear ratio to look for. if I keep the sm420 transmission?

[60-66]

Stock gears in a K10 Chevrolet is 3:73

[Arne]

Depends on how tall tires you plan to use.