Cam question

[885.0conv]

I was wondering how much of a difference I would get if I where to change the stock cam and which cam to go with. I have not put the heads and intake on yet.

 

[vristang]

Wait until the heads go on...

 

[885.0conv]

Also the guy I bought the heads from had a cam special made but was trying to get something cheaper. The specs he gave me for the cam are:

Duration 218/ 218 e 50
Lift 533 / 533
Intake lobe center 106

I know a little about the numbers but not enough to make a good decision about a cam.