Weight may be a factor. I removed the kicker from my 228 and had to install 100# of lead on the port side (side the kicker was) to keep my boat sitting even in the slip.
If your boat sits even in the slip w/o a kicker, relaize that you will be placing 95# on one side of your transom, and it will heel to the side slightly unless you get counter weight.
I believe the only logic is to install opposite the ladder. I've seen Gradys with kickers mounted on either side, so i don't know if there's a best side or not. If you have a ladder, probably doesnt make sense to move it, just b/c people say "mount on the port side".