hey everyone, im kinda new to evom and new to my evo and i did most of the basic mods (intake, exhaust, gauges, fuel pump, tune, ect.) and im thinking of doing cams next because many people have told me its the next good bang for your buck step. i was considering the hks 272 cams but i have a couple of questions about them and i tried looking up but cant get a direct answer, all of the places kinda left me to my own conclusion but i dont know enough to do that. my car is a daily driver so im not looking for anything to insane, i dont beat on my car too much because its my ride back and forth from work but i do like to pull it once in a while, my finish goal is only about 400, 450 hp. i dont really plan on changing the turbo (unless the price is cheapppppp)(and i understand that cams aren't the only answer to getting 400hp this is just what step im up to) i want the hks because i can get them pretty cheap, and hks has seemed like a durable brand. some of my questions are:

1. can i use them with my stock springs and valves? (some say yes and iv heard some people tell me no)
2. i'v heard some cams cause cars to stall when at idle do the hks cams do that?
3. are there any common problems with the cams?(typed this into google and the only thing that really came up was supra and dsm problems not evo)
4. what is the difference between the "old version" and "new version" hks cams?(typed this in only cam GEARS came up)
5.when installed what are some common problems the car will have? (i'v heard when putting out too much hp you could easily snap you timing belt)
6. if i get cams are there any other new parts i "must need" to have in order to install the cams, or can i just swap them out with the stock? (typed this in and there are only "suggested" mods to do along with the cams nothing "must have")
7. how do i know if there fake? (on the dsm forum they were talking about something about M005 & M006 being engraved on the cams)

8. are there any other good cams that i could get a bang for my buck? im trying to keep it under $400 (i know you get what you pay for but like i said im not looking for anything crazy i dont take my evo to the track)(typed this in and got many different opinions im looking for a reason why you think so)

thanks in advance for your help