Due to running a different set of stock rear end gears, my speedo is way off on the truck, and I'm running an SA tranny. My rolling diameter isn't far off from stock, so a stock driven gear from an early truck would put me back near correct. Does anyone know if a 74/75 ribcase speedo driven gear will work in an SA tailshaft driven by the regular coarse SA drive gear?

 

speedo gear from REPU tranny? yes

 

Just to be clear, I can leave the stock drive gear in the tranny, and swap on the driven speedo gear assy, right? No cracking open the tranny to slide the drive gear off the output shaft?

 

follow the speedo cable to the tranny. unbolt the 10mm bolt and claim. speedo gear should pop-out.