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Marty68 · 10-18-2019, 01:48 PM

.76 is the final ratio of a 700r4. with a 27 inch tire your rpm at 65 would be 1893. likely not enough torque to keep things moving without more gas pedal.
3.08 gear 1:1 final ratio with th350 puts you at 2500 rpm... maybe a tad high.
3.73 gear at final ratio of.73 27" tire puts you at 2293 rpm. enough rpm to have throttle response.
my advice would be if you are stuck on 3.08 gears go th350.
if you are stuck on 700r go 3.73 or 3.42.
3.42 is most common in 4x4 s10s which is a usable width for these trucks.. like posted above develop a ideal final result. plan accordingly so you dont spend money twice.
all info from this http://www.csgnetwork.com/multirpmcalc.html
and this https://tiresize.com/calculator/
figure what size tires you want with final stance plug that tire size in to find diameter. plug that into rpm calculator. good rule of thumb would be ideal final cruise speed of 60 mph between 2100 rpm and 2500 rpm.

10-18-2019, 01:48 PM	#27
Marty68 Registered User Join Date: Nov 2014 Location: west coast, Wi Posts: 534	Re: Rear Diff questions .76 is the final ratio of a 700r4. with a 27 inch tire your rpm at 65 would be 1893. likely not enough torque to keep things moving without more gas pedal. 3.08 gear 1:1 final ratio with th350 puts you at 2500 rpm... maybe a tad high. 3.73 gear at final ratio of.73 27" tire puts you at 2293 rpm. enough rpm to have throttle response. my advice would be if you are stuck on 3.08 gears go th350. if you are stuck on 700r go 3.73 or 3.42. 3.42 is most common in 4x4 s10s which is a usable width for these trucks.. like posted above develop a ideal final result. plan accordingly so you dont spend money twice. all info from this http://www.csgnetwork.com/multirpmcalc.html and this https://tiresize.com/calculator/ figure what size tires you want with final stance plug that tire size in to find diameter. plug that into rpm calculator. good rule of thumb would be ideal final cruise speed of 60 mph between 2100 rpm and 2500 rpm. Last edited by Marty68; 10-18-2019 at 01:54 PM.