If your running a brushless, no, i wouldnt bother because the alloy would just wear down way to quick. i would suggest steel outdrives, much stonger.
I run a brushless, 7.5, & ive gone through 2 sets of alloy prop shaft joints, 2 alloy prop shafts, 1 pair of tobee craft outdrives & i even managed to snap 1 pair of tobee craft universal joints! I now run tamiya universal joints, tamiya steel outdrives, & im about to purchase GPM titanium prop joints & a carbon prop shaft.