Rear differential help please

[Woodnears]

I am asking for your help or basically telling me what I need to do to get the most out of this truck. 68 C10, currently has a 4.8 ls engine backed with a 4l60e. The rear axle is stock with 373 gears. I am running 22x9 wheels and I’m curious if I need to consider changing gear ratios but have no experience with this area.
Anyone else running a similar setup that could give some advice? It’s obviously not a speed demon but I do want a quality built rearend that will handle any future upgrades. Am I asking too much?

[kwmech]

I wouldn't bother with the 3.73s and the overdrive

[Woodnears]

It seems a little bogged down. What would you bother with?

[mongocanfly]

What size tires are you running?
The 4.8 is no powerhouse, but you may need a good tune...did you run it on a chassis dyno after your swap?
The cost to swap gears isnt gonna be cheap, but 373s should be fine with a 4l60e..unless you have really tall tires

[Woodnears]

Tire and wheel combo are roughly 31”

[geezer#99]

You’re running about 2 grand at 70 mph.
Are you carbed or injected?

[mongocanfly]

Heres a rpm calc to help you out...
http://www.csgnetwork.com/multirpmcalc.html

Your turning a little over 1800rpm at 65mph..with a 31in tire and a .7 od with 3.73s
I try to set mine up to turn 2k at 65mph..seems to be the sweet spot for me.
If you were starting from scratch I'd say 4.10s...since your already 3.73s I wouldnt waste the money to swap it
But your 3.73s should be fine if you have a good tune..

[Woodnears]

Thanks for the calculator link, that’s handy. This rearend is leaking anyway and needs new seals, bearings, axle. The Way I see it needs rebuilt anyway. Is it worth going to limited slip?

[mongocanfly]

In my book,It's always beneficial to add a locker...the Eaton trutrac is one of the best....

[SB'72]

Trutrac is a great unit

[Ziegelsteinfaust]

On my 07 gmc with a 4.8 I ran 4.56, but if I had it to do over 4.11's or 4.33's would of been my choice. I had stock steel 17's though.

The 4.56's were not bad, and suited the truck well. Just ceuising over 75, a.d it was always wanting to down shift.

[b454rat]

Plus those wheels ain't helping any. I have 20s on my tundra and are HEAVY.

[gmc684x4]

Why such a tall tire on a c10 i can see taller tires on a k10 ?
C10 tire hits the range of 28.5 inchs tall usually

[Woodnears]

Here’s a pic of the truck! Think I’m gonna try a trutrac, I’ve heard a lot of good things about them.