Husky,
I'd probably go ahead and do something like that if I didn't actually want to use it in the woods. No doubt guys like Ken and Dennis really know there stuff. Since my only knowlege of options in this regard is from the Madsens and Walkers web sites as well as threads like "Greffardized" here (where I actually learn more about you people than the topics, absolutely hilarious), I'm thinking that what I want is a saw that has noticeably more power, still mantains good reliability and isn't so fine-tuned that you have to re-jet the carb when the air temperature changes by 10 degrees F. I certainly understand that, within reason, an increase in power doesn't necessarily mean that you will take a major hit in reliability. I also suspect that at some increase in performance, you will end up with a saw that will spend more time in the shop than cutting wood. As I said, I won't use the saw professionally, so assuming that I run and take care of it like it should be, I would expect that with a given set of mods, it would be more reliable for me than for a pro who counted on it to put food on the table. Other than general mantainence, my 266 has never been apart since I bought it in 1987, and I use it from early spring till late fall, probably about an average of 5-10 hours a week.
So, given my background and conditions, if you wanted to still use the 3120 for woods work, what would you have done to it?