4.88s or 5.13s, what would you run?

[99'Subourbon]

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4.88's will bring you back to around the stock effective gearing

Is that graph relative to our trucks? 4l60e? Final drive is a determining factor as well.

 

[Crash]

No, that's 1:1 not overdrive. It makes this chart universal to any truck that way.

 

[99'Subourbon]

No, that's 1:1 not overdrive. It makes this chart universal to any truck that way.

Gotcha! Taking that into consideration, I am not sure if I wanna go 4.56s or 4.88s with my 33s. I would go 4.88s, for when I get 35s... but that won't be for quite some time as the 33s are new. I have to imagine 33s with 4.88s would make for some insane low end power, but be a dog 60+.

 

[thz71]

It wont be a dog youll just be turning a lot of rpms

 

[99'Subourbon]

Yeah, thats what I meant I guess. Fuel economy and Passing speed will be lower at 65+

 

[Crash]

Here play with this, it will help you decide.
http://www.teammfactory.com/gearcalculator.php?kmh=0&tirewidth=315&tireprofile=70&wheelsize=17&tirediameter1=37.&maxrpm1=5000&finaldrive1=4.88&gearratio1=3.059&gearratio2=1.625&gearratio3=1.&gearratio4=+.696&gearratio5=&gearratio6=&trannytype=&tirewidth2=265&tireprofile2=70&wheelsize2=17&tirediameter2=31.61&maxrpm2=5000&finaldrive2=3.73&gearratioa=3.059&gearratiob=1.625&gearratioc=1.0&gearratiod=.696&gearratioe=+&gearratiof=&trannytype=&tranny=Calculate+Transmission+1+%26+2

 

[Shorty01GMC]

I ran 5.13s in my nbs on 37s and 38s. highway and city driving was great, but towing in 3rd was ridiculous... next time around i'll do 456 or 488..

 

[jadaven]

Truck looks good btw!!!

Thanks!

 

[Ecorrales]

I just got my lift finished up. Running a 6" RCX and a 3" BL on 37" tires. Going to regear next month.

I do mostly highway driving 70%, 25% city and maybe get off road once in a great while. I'd also like to have a
decent tow capability if the need came up.

Truck is a 1990 RCSB K1500. 5-speed, 350TBI with 140K on it. Stock 3.42s, which obviously suck with 37"s

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What wheels are these?

 

[1989GMCSIERRA]

I ran 4.56 on my 89 when I had 35s. Also ran them with 33s.
I regeared to 4:10s as I’m taking off the body lift and going to lower it slightly with either 275s or 295s