All things being equal, having both tuned right for the same motor will you notice a differane between them? performance wise or other. thanks

I would have to vote no. No performance difference. The beauty of the flat slide/rack carbs would be the lighter pressure it takes to open the throttle, and the fact you shouldn't have to worry about your carbs going out of sync any more.

thanks

It's all a matter of personal preference.

Jetting is my thing, and personally I prefer the Vm roundies

Pros for roundies - can be individually removed and jetted
- Can jet midrange in seconds (flat are much longer to do)

PRos for flats - Can sync carb from bench and simply adjust idle when running
- Much lighter to pull 3X38 flats than 3X38 rounds

Personal preference.

Also, jetting is usually around 80-100 points(cc/hr) more for the roundslides, for the same engine setup.

Example: 99 T-cat with roundslides. Factory jetting is 430's
01' T-cat with flatslides. Factory jetting is 340's.

I was always told that the flatslides will give you a smoother throttle response and quicker acceleration,,,, I take it that that is false,,,,

puree, you are correct, they do perform better. The reduced throttle pull and carb sync. aren't the only reasons flatslides are stock on pretty much every carb sled out there now.