If your local organization allows it, you should go with a hand throttle, because if your flying around a corner, mower bouncing every wich way, and your tryin to keep your feet on the footholds, how are you going to control your throttle when you can barely keep your foot on the pedal? Whereas on a hand throttle, it's ALOT easier to control the throttle (and it looks cooler to
) Puttin a foot throttle on a mower is like puttin one on a bull and goin to the Rodeo.
Another thing, i don't see why you had to lenghten the frame, because like tractorman said, you are much better off widening the frame, or not even touching the frame at all!!! Also, adding that extra metal to your frame to lengthen it just added excess weight to your mower!
Last thing: if you have a copy of your racing group's rules, can you Please post them here for us??