Haha I wouldn't push those rods and bearings!
I don't even want to think about what the transmission would do under more power. You would just need to make sure you made very clean shifts I suppose - treat the clutch like an off and on switch so you don't burn it.
You would get much better performance out of a custom camshaft and some head work. At least the headwork and shaving it down would be cheap and give you a boost in performance. I'm sure Sam knows the situation inside and out. There are lots of tricks that can drain your life away trying to gain some more performance. An electric ignition kit would really help too. It's fun to think about I'll give you that.