Granny geared 71' K10, I need to go faster...

[bobbylong]

Bigdav160 & SweetK30 – thanks for the info, I had no idea what I had and would have taken forever to figure it out.

HO55 – The truck is in eastern Oregon just over the Idaho border. I’ll take your advice and tailgate a Prius to check my speed. Should have no problem reading their speedo from 3 feet away.

El dorado Jim – Sorry bro, not for sale.

Jeffahart – not sure about the fan, but that’s a good point.

Special-K - I’m not wanting to race imports on the freeway or anything, but I’d like to be able to drive a consistent 70MPH. I’m really thinking the 700r4 may be the way to go.

Richard – Good idea, I’ll give that a try. AndyH1956 are you saying I need to spin both wheels?

Bilt4me – Good eye, I’ll definitely shore that up before I drive cross-country.

You guys are all a wealth of knowledge! I really appreciate you advice with this. If any of you live in the DC area and want get your hands dirty on it, I’m sure I could use the help there too.

I’m gonna lift it, go with a bigger tire and wheel and I’m really thinking about a tranny swap. I know some of you are against that, but… it is what it is, and it is mine. Building something cool is a much fun than driving it.

[Richard]

Originally Posted by andyh1956

Only turning one rear wheel will give an erroneous reading. The spider gear to side gear ratio will do that.

Curious how the spider will change the reading? I do not believe it operates like a planetary gear set. I think you will find that the opposite wheel will tend to rotate in the other direction with an open diff and both wheels off the ground. That can lead to an "erroneous reading"

[andyh1956]

Originally Posted by Richard

Curious how the spider will change the reading? I do not believe it operates like a planetary gear set. I think you will find that the opposite wheel will tend to rotate in the other direction with an open diff and both wheels off the ground. That can lead to an "erroneous reading"

It really don't matter which direction the tire rotates for our purpose here. With one wheel stationary then the spiders WILL act as a planetary. When the carrier is turning with both axles equal in traction, the carrier drives the cross shaft, the cross shaft drives the spiders, which drive the side gears which drive the axles. No gears are turning inside the carrier at this point so the axle speed to carrier speed ratio is 1-1. With say the left side gear stationary (left tire on the ground) as the carrier is turned the spiders are driven by the cross shaft around the stationary side gear. The ratio of side gear to spider is about 2-1, that is the side gear has twice as many teeth as the spider, so the spiders will drive the right or rotating side gear at a different speed from the carrier, which is where the erroneous reading will come in. Ever notice when you're on your tractor & you apply say a left brake that the tractor speeds up while making the turn? Same forces at work thru the diff on the tractor.
When yall get time jack up one side of a truck with a known ratio & try it.
If you jack up both sides & mark both sides & the pinion then rotate the drive shaft be sure to have some one on both sides of the axle to make sure the tires stay together, brakes dragging or other forces can make one tire fall behind the other as they are turned.
I know this is confusing, may as well pull the cover & count teeth, our old trucks always need something else fixed in there anyway!

[special-K]

Fresh lube is good.

[bobbylong]

Ok fellas, I’m looking for lift kits but I have a few questions. What would the stock ride and tire height be? I really like the stance of the truck now and don’t really want to go much higher, but without knowing the stock height I don’t have a starting point. The truck could already have a 2” lift for all I know. Also I’m assuming these trucks came from the factory with a rake from back to front, so would a 1” offset in the lift level that out? Lifting it will help improve suspension travel, and allow for a taller tire helping me keep up with traffic. Not to mention, it’s looks cool!

Also, any recommendations on lift kits? I’ve been told Off Road Design makes a good product.

[sweetk30]

your pics from before show stock leafs in the front end. so I would say no lift in it yet.

[bobbylong]

Originally Posted by sweetk30

your pics from before show stock leafs in the front end. so I would say no lift in it yet.

Any idea what stock ride height is? tire height?

[BILT4ME]

Most likely stock tire size is a 7.50-16 bias ply mud/snow tire. Generally, they were about 31" OAH.

"Stock Height" is a relative term, and it depends on where the measurement is taken.

Someone here has frame dimensions and I believe there are dimensions from the frame in given areas to the ground.

Some folks try to measure from the center of a hub to the bottom of a fender lip. That will identify any "lift", but I'm not sure that it was ever a "stock" dimension that was documented.

You may be able to find an overall height dimension to the top of the cab, but that could be influenced by tire diameter and what YOUR truck was equipped with.

The 68 K20 we had lots of years ago came with 7.50-16 mud tires, but we changed tires many times during the life of that truck, so the overall height would have varied. It was also the HD version and the "stock' dimesnions are usually given from the base model truck and that MAY have been using street tires, not mud/snows.