Nope, we all left town!
The "right" setup could get you into the 80's but that's a SAW boat, not one for oval racing. If you can get one solidly into the 60's that should be plenty fast enough.
I haven't a clue right now as to what prop to use as I'm still working with a lot of them.
No, it's really not too big as there are some guys dropping those engines into the smaller Sprint Cat's. The CG has to be way forward in the hull as you might have to mount the motor up by the front bulkhead.
Why did you post in the Fast Electric forum? You post here and wonder why nobody immediately responded? It's kind of obvious. Give people a few minutes and post in the correct forum. There aren't people sitting here waiting for someone to post a thread, it doesn't work that way, sorry.