3 Speed to TH350 Speedometer cable?

[ChevyGearHeads]

I have a '68 C10 LWB and swapped from a 3 speed on the column to a 350 turbo and am wondering which speedometer cable gear to use? Any information is greatly appreciated

[midniteblues]

pretty you can use your original speedo cable. but you might have too rout it a lil differnt.

[ChevyGearHeads]

Oh, I mean't the driven gear, the different colored plastic ones?

[old Chevy guy]

If you mean the one on the end of the cable drive, I should think the same one that came out of your 3 speed should work for the 350. Your issue is the one that drives that gear that's on the output shaft inside the tail. Not sure that one will interchange with the 350. You need to hook it up and check your odometer on a measured mile and see if it comes out even . If its 10/10ths to a mile the speedometer should be accurate. If not then you have to change gears. I'm certain there is a table for that somewhere, its come up before.

[geezer#99]

Maybe this one.
http://www.transmissioncenter.net/sp...____va.htm#350

[68gmsee]

Originally Posted by ChevyGearHeads

Oh, I mean't the driven gear, the different colored plastic ones?

I used a GPS on my truck to check my actual speed. I wrote down the actual speed compared to what the speedometer was showing at different speeds up to 70 mph. This will give an idea of which gear to use. I only had to change the driven gear but I've heard that it's easy to change both on a TH350.

Found this: http://www.chevytalk.org/fusionbb/sh...hp?tid/165567/