Bendder,
thanks for the info, most of it i knew or assumed. mainly the heat treating is what i assumed. i don't think it was done to the halfshafts i have after looking at the other untouched SD1 halfshafts i have. the person i got these from had them in tr7 with a modified SD1 engine (just cam and carb mods).
see picture links below, the first picture shows two halfshafts one damaged and the other not. the other picture shows the spline damage to the one halfshaft.
It looks like i"ll be getting the good set spline area heat treated before i install them.
http://i155.photobucket.com/albums/s316 ... C04468.jpg
http://i155.photobucket.com/albums/s316 ... C04465.jpg
<b>"GETTING SPEED OUT OF A LOW POWERED CAR IS OFTEN MORE REWARDING, THAN WITH TIRE-SMOKING BRUTES" </b>