hey, i have a 1989 irocwith 305 tpi and 700r4, it has the stock 3.23 posi, i am planning on installing 3.73 gears in the rear. first has anyone else put in 3.73s and how good is it? and would i have to install a different speedo cable or maybe a gear? it would change the speedo read out right?

 

Lots of people have done it and they all say they love it. Your RPM will be higher and you're speedometer will be off by maybe 2 mph. You'll need a different driven gear in the tailshaft of the transmission. Which one forsure, i don't know, there's other people on this board who can help with that.