speedometer hookup help

[stan79chevy]

as some of you know im in the middle of a rebuild on my 79 we did the motor last summer and the extra power killed the tranny, transfer case, and the rear end.. since then i have gotten the th350 completely rebuilt, replaced the half ton axles with 3/4 ton stuff. and i got a 205 transfer case instead of the 203. i have the axles in and they have 4.56 gears. my question is my speedometer is going to be way off because i originally had 3.08 gears. i still have the 205 that came out of the truck that i got the axles from. can i take that input thing off that one and put it on my other 205? is that where the "gearing " thing for the speedo is? or is teh gearing thing in the speedometer itself? my truck is a 79.. the axles are 77 and the transfer case is a 70. thanks

stan

[71swb4x4]

Your speedo gear should be behind this.
This is what the speedo cable hoks up to on the transfer case.
I could be wrong but I think there is a gear behind here that you can replace.
Shawn

[stan79chevy]

then the speedo cable goes into the box. my 203 was the same way but the 205 i got out of the parts truck just has the cable going into the case like the one in your picture. is it the box that has the gear in it or is it inside of the case?

[71swb4x4]

I think you may be right about the box. I forgot all about that. There has to be someone on here that knows for sure.

[TATE228]

just put big enough tires that it equals out

[stan79chevy]

Originally Posted by TATE228

just put big enough tires that it equals out

i wish i could do it that way but going from 3.07 to 4.56 is going to take alot of tire to even out. right now i have 33's im thinking ill go to 35's when the money is right

[stan79chevy]

heres my 203 and it had the box

[Cethern]

If you were to unscrew the big nut there is a gear that your speedo cable gets hooked up to in away. But from the pic you put up it looks like you have a speed corection deal on it already but I could be wrong. The 205's I have had in the past have had a metal gear in them I'm not sure if thats the case with all 205's. All you should have to do is hook up your speedo cable and your good to go.

Cethern

[johnleewilson]

go to a speedometer shop they will check your speedometer and then put the appropriate ratio wizbang on there for you shouldnt be too much

[stan79chevy]

go to a speedometer shop they will check your speedometer and then put the appropriate ratio wizbang on there for you shouldnt be too much

i cant just give someone some money for something i can figure out on my own. i have a few 205's and my brother in law has 4 or 5 and some 203's as well. ill take the little box off each of them and swap them in and out of mine until i get the box that is what i need. im guessing that little box is a gear reduction of somekind. im thinking that if i get rid of the box and run it straight into the case on that gear thingy in there it should be factory for 4.56. the truck i got the 4.56 gears out of didnt have the box at all.

thanks
stan