Hi I am new to this site and have a few questions about what i want to do to my Bonneville. I have a 1999 Pontiac Bonneville SLE and i would like to supercharge it. the car has a 124,000 miles and runs amazing. But I am not sure what to do, either to build the series II engine up and but a kenne bell on it or to buy the the series III with the supercharge on it already and mod it from there. What is better to do because I am hearing the it is better to build the series II up and Whipple it.

Kind of a loaded question. I'm also planning to supercharge my own 99 SLE. I've already got the parts, too. One huge issue is the transmission, which likely won't hold up for 40K more miles with my current mods. A Kenne Bell supercharger is a big deal. Its cost is huge, and you really shouldn't put it on your car in its stock form. A Series III is a different kind of engine than what you would have with a Whipple and 9.5:1 pistons. Are you just surveying basic options? I think it would be cheaper to go with a lower intake manifold from a Series III engine and also to get the supercharger, L67 throttle body, L67 to Gen 5 TB adapter, L67 fuel rails, heads, and an SS M90 pulley. That would be a relatively cheap way to go supercharged. A Kenne Bell supercharger is a whole new game, but it would be cool to see you try it out.

Keep in mind you don't just drop a supercharger on the engine and off you go. You will also need to do a lot of tuning. So you will need software like HP tuner, no to mention the skills needed to do the tune. Dropping in a ready built engine and matching PCM will save you a lot of work.

yes i know i will need to tune the car and everything but i was just going over some options that i would have. what i had in mind is to take the series II engine i have know and put in forged internals and supercharge it and put in a new transmission in. Or two go the series III route with the supercharger on it already and mod it from there just like u said because it has a lower compression ratio 8.4/1. but thank u for the comment.

I think we should wait and see if Rad'* project turns out as planned and then move on from there.
This way Rad will iron out the problems and you can learn from him.