what will happen when i put in a set of 3.73s?
I know the rpm will be higher, but will it hurt my transmission or interfere with the computer?
is there a guesstimate for how much the speed is off?
is it off in the spedo only or in the computer as well?

I bought a 3.73 posi rear end complete with discs, for 100! I changed the oil to lucas 80w-90 heavy duty. put on new pads, and Im getting ready to bolt it in. Any suggestions or advice before I do the install?

when I did mine the speedo was off quite a bit, like it said I was going 50 when I was going 30, 70 when going 50 and so forth, It can be fixed you just have to change the correct speedo gears into the tail shaft of your transmission. Do a search you find what you need

I searched but never found a post explaining how to install the speedo gears in the transmission (700r4). I found that i need a 44 and a 15....

http://sethirdgen.org/vss.htm

JamesC