For belt slip all you need is a good set of idlers to go along with the upper pulley. If you go with a 2.93 then all you really need is a 100MM upper idler pulley. That will give you enough belt wrap to prevent slippage. As for the different stages of porting... As Stiegemeier progressed in the Eaton M112 porting business they learned a few new tricks along the way so now they offer different "levels" of porting depending on how much HP your looking for. Each successive port opens up the blower so that it flows more air. Check out their website for more info... http://www.stiegemeier.com/index1.html U.M.
I will second that. I just had mine tuned to a "conservative" tune. My biggest problem was my MAF pegging. On 91 octane I made 466/458 at 16 degrees timing WITH a stock H-pipe. On 93 Octane and 20 degrees, I made 491/477 with a slipping clutch. I also pegged out at 5500. You will not see much improvement with just a upper, ESPECIALLY a 2.93. Steg recommends a 2.93 w/ a 6# lower or a 2.8 upper w/ 4# lower. But then you will need a MAF extender and a tune. Possibly a BAP. I have seen these cars his the 550 rwhp mark fine, but I have seen more run out of fuel at 510 mark too. Bottom line is that you won't see the quoted gains without fully utilizing the increased airflow. And you need the boost to do that. My mods are in my sig.
