You are probably better off if you do use one but when I did mine I just cleaned up the case and cover VERY well and laid a bead of silicone in the groove. No problems to report thus far and it has been a few years.
I havent even gotten the stuff yet Gregg suppose to be here by Friday. Then I still have to wait for a buddy of mine from back home to come and do the install cuz I have no friggin clue ...
Yeah, it is a good idea to have them done right. Otherwise, you may be in the same situation sooner than later. Unfortunately, I think I am going to be in that sooner boat.....
I know the feeling brother but at least you now know what is done. I never planned on learning half of what I know when I bought my car. I have broken and fixed more things than I can tell you. I don't regret any of it.