best engine for autocross = stock... unless youre bored and masochistic like me. :exnbp:
Like CivicSiRacer said, you've got a pretty good STS setup now (or at least after the swaybars), and you could be a very competitive racer if your driving skills are up to the task.
If you plan on autocrossing, and would like to move into Mod (or just definitely want to swap) H-series is too heavy, and really its just overkill in terms of power.
I know I want to swap because my vx motor is very old and dying and I'm bored with 90 hp. I raced stock for 2 seasons and STS for one season. Personally, after a lot of thought, I've decided that the B20 is the way to go for me. The main reason here is that you'll use a wide, torquey powerband more than just high-end power since you (or maybe just me
h: ) cant really concentrate on keeping the engine on boil in such a restricted (time and space) situation. I hope to do either a B20z, or B20B with a little bump in compression. If youre going Mod anyway, also invest in a limited slip. I can feel how one would work wonders for me even with my pitiful vx power.
Its an expensive and pain-in-the-ass road, and in the end, you might just end up being beaten by a bunch of experienced drivers with deep wallets. So unless youre sure, I'd stick with what you've got. :thumbup:
:edit: I'd also suggest that you keep your GCs rather than paying for full c/o's. Main reason here, is its CHEAPER, you have more options (replacement springs in any spring rate are only $50), and its easier to replace a part of the system rather than the whole damn thing if something breaks.
If your tokicos die, buy Koni Yellows. I used to race on illuminas, which were pretty good, but the Yellows are just awesome in comparison.