Sounds like a fun contest.
When it comes down to it, the prop selection and pipe setup will probably have more to do with your top end speed
Good idea balancing the speed aspect of the event with a pattern sequence. Transition and idle will be just as important as the top end.
Jett does have a full size 'big block' .61 listed as a special order on the web site - cost the same as a SJ-90L - Dub has not built one in years. Was for special events which specified 10cc. I guess he can still build one if needed. The SJ-76 or SJ-90L fill its spot in the engine size range. The Jett 60LX is a "40" size engine - its powerful, and might keep up with a 'big block' .61 engine with a full pipe installed.... but in the Tipo, the lighter engine would require some very creative CG adjustments.
The Novarossi is a good engine. No doubt that is going to be fast.
The old YS 60 RE is mighty powerful. Has no quams turning 14,000 rpm - my old Aurora went like heck with the short pipe and a 11x7 on the front.
The old Rossi 60 RE I had in my EU1-A was a sweet engine. A few mods - High timed liner, installed a 9mm carb - 10.75x7.75 prop....... that was a screaming power plant
Didnt idle extreamly well.... but it had great top end
The OS 61 pumper was good for 11.5K rpm with a 11x11 up front. That brushfire was not slow.