gear ratios

[1983Blazerkid]

i know i know ive looked it up but the charts say for a manual trans or whatever. well i have a 700r4 so i know its going to change things. but which way i want to run 38s for now but ill prolly back it down to 35s or somewhere in that range. just want to know what gears i should be looking for. ive got a 350/ 700r4/208 thanks for the help cody

 

[NEK5]

I think you could get away with 4.88s in the 35-38" range....

 

[CB77GMC]

4.88 or better for 35's to keep from killing tranny.

 

[Leper]

4.56 for the 35"
5.13 for the 38"
4.88 in the middle
What do you do with the truck?

 

[loafer]

Take the RPM # off the manual charts you were looking at (I assume a 1:1 transmission ratio) and multiply by 0.7, which is the OD ratio of the 700. In OD the torque converter is locked, so you don't have to consider any slippage in the calculation. You can also calculate your RPMs"

Engine RPM = [((miles/hr) x 336) / (tire diamer) ] x axle ratio x transmission ratio

Example: [(65 x 336)/35] x 4.56 x 0.7 = 1992 RPM

There are calculators on the web to do this, but it's handy to know how and do it yourself.

i know i know ive looked it up but the charts say for a manual trans or whatever. well i have a 700r4 so i know its going to change things. but which way i want to run 38s for now but ill prolly back it down to 35s or somewhere in that range. just want to know what gears i should be looking for. ive got a 350/ 700r4/208 thanks for the help cody

 

[Chrisblazzer89]

I will sonn have 38x14.50R16.5 super swampers TSLs And I will only have 4.10s I will let you know how it feels.

 

[1983Blazerkid]

thanks for all the info guys cody

 

[1983Blazerkid]

i mostly just play with it. dont know if im going to ever drive it on the street again. but i have 35s now and the gears suck. so im going to fix that. then maybe if it helps alot i might start driving it again

 

[Avery4jc]

I've got 4.10's with 38.5's that measure out to 37....it feels fine and thats even with a slipping tranny. We have the same exact setup too...sb350/700r4/np208...
Something else to keep in mind is the 700r4 has a pretty low 1st...but again it depends on what you do with it...If you aren't going to keep it on the street just go 5.13's and be done with it...if you might keep it on the street go 4.56/4.88 (probably won't see a huge difference between the two).