If having this installed in a stock engine (no new heads or intake) I personally believe it's a waste of money and effort. In my opinion, if you're going through the hassle of having to pull all of the accessories, intake, and having to go through setting the valvetrain up, it's just easier to pull the heads and put new ones on while you're in there. Doing all of that depends on your budget of course. An E cam isn't even that great of a cam and if you are using stock heads, do yourself a favor and at least get a split pattern cam that favors the exhaust since that's the biggest bottleneck on stock heads.
If having this installed in a stock engine (no new heads or intake) I personally believe it's a waste of money and effort. In my opinion, if you're going through the hassle of having to pull all of the accessories, intake, and having to go through setting the valvetrain up, it's just easier to pull the heads and put new ones on while you're in there. Doing all of that depends on your budget of course. An E cam isn't even that great of a cam and if you are using stock heads, do yourself a favor and at least get a split pattern cam that favors the exhaust since that's the biggest bottleneck on stock heads.
To actually answer your question, all that needs to be done is check that it was installed right by degreeing it. You can degree the E303 by the ICL method, it's pretty easy to do. Chances are it will be fine so there's no real 'adjusting' to do per say.
stock cam swap all gains are minimal. look at me for example, only reason I threw in the cam is because a of a blown head gasket, i figured while im down there ill just swap the cam for later use. didnt have the cash at the time for new heads