i forgot, somewhere sells 12.2:1 compression pistons for like 450 bucks, but have fun with the knock unless u run 100 octane or so. i myself was going to put the SVT pistons in my car, my friend has 10.2:1 compression pistons from his svt focus he gave me, just sitting in a box now.. :/ scared to put them in with the s/c..
just buy a new head from ford. 795 bucks. i had a site with all the hp gains but i'm at work and i dont have the link. but with all the "bolt ons" the car was at 151 fwhp. with the addition of the head it jumped to like 173. not bad for like a total of 2 grand.
but i got like 160 so.. i don't care