well, I prefer the BA/BF engines, it just makes things easier for me all around...as for VCT, i'll use it if it has it(I'm sure I can get MegaSquirt to run it(even if I have to write the code in myself) but its no big deal if it doesn't...I have read that NA engines when turbocharged have issues with valvesprings? having turboed more than a few different NA engines myself, I'm wondering why that would be? Valvesprings in my experience have nothing to do with boost, unless you are using big cams, and if you're using big cams, then most of the time they arent meant for forced induction...or maybe I should say in my experience I havent run into valvesprings as an issue(I suppose theoretically if the springs were weak enough the extra cylinder pressure might force the valves back open?)