CK5
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WL: Crusty 1985 K20.

4.10:1 is the ratio that I would run in that combination, too. It's the running 4.56:1 with 31" tires and no O/D that seems screwy to me. :screwy:
My dd with the 4.10s with a 700 and 33s is too high.


See you don't get it. The 6.2 700 and 37" will be getting 5.13s.
 
My dd with the 4.10s with a 700 and 33s is too high.


See you don't get it. The 6.2 700 and 37" will be getting 5.13s.

I'm not surprised. While I am quite happy with my "slow" gears (3.08, 700R4, 29"), very few builds on here go that high. @Massboy is the only one I can think of that has gone higher (3.08, 700R4, 31"), and he's got another 6.2 truck. But that's ok, my truck is set up for highway cruising. It never sees rocks or difficult trails.

Someday I may build a rig that needs deeper gears, but so far I'd rather have the smoother high-speed cruising than the extra low-end grunt. :dunno:

So, yeah, Martin, I'll not be needing CUCV axles for a while (at least, not 1-ton CUCV axles). But it would be fun to try them out. Prolly get hooked on them for lower-speed driving. Maybe if I found local enough offroading opportunities the street manners wouldn't matter so much. :thinking:
 
Not sure how anything pulls 3.08s and a .70 overdrive. That is a 2.15 equivalent final drive ratio.
 
Not sure how anything pulls 3.08s and a .70 overdrive. That is a 2.15 equivalent final drive ratio.

It's no speed demon off the line, but I've never had problems keeping up with traffic unless I was trailering. And even then, it's no worse than a typical small-engine 1/2-ton. I wouldn't pick those gears for a dedicated tow rig, but they fit their purpose quite nicely. I do typically have to downshift on anything steeper than a 5% grade. But I live in flat enough country that this doesn't happen often enough to annoy me.

There were gas rigs with 2.73 gears...this can't be as bad as that was. :dunno:

My Suburban has 3.73 gears with .70 overdrive & 31" tires. It is much nicer for pulling loads. But overkill for street cruising at my altitude.
 
3.08s and a overdrive is horrible. My k10/had it from the factory. 3.08s and a 1 to 1 final is fine. I have one trail rig and it has 5.38s. In my opinion 3.73s are just about the min overdrive to work and not yo-yo.
 
Stein has 4.56s a 400 and 37s and gets 18 mpg and has plenty of power. He runs it 65+ without a problem.
 
This truck has 3.73's, an SM465, and 36's and get some mpg and has less than plenty of power. I run it 65 and the unbalanced Swampers let me know.

Martin
 
Is the data plate on the door?

Martin

Yes. I though yours was missing. :dunno:

Edit: To clarify, there is one plate on the driver door (with generic vehicle dimension info) and one on the door jam (with vehicle-specific info).
 
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Meanwhile, back at the '85 K20 ranch, that shaft is not broken.....

118-1.jpg

Martin
 
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