To make it live you want the longest rod you can find, less rod angle pushing the piston into the cylinder wall and a lighter piston/rotateing assembly, plus it helps to NOT rip the pin out of the piston as acceleration forces are smoothed out. Find an early 230 casting block, get is sonic tested and use aluminum main caps and mabey even aluminum rods to absorb shock to the block, a good main cap girdle and tall fill of hard block and REALLY QUALITY machine work is about all you can hope for to make a stock block last a little while. Just have the deck squared up not milled a ton, that extra meat will help head gasket seal and block torsional rigidity, you don't have much to start with so don't squander what you do got. To keep the valves from floating you should probably invest in titanium pushrods, retainers and valves, lightest lifters you can find (solid roller of course) and replace your springs every so often. Get one of the good head guys to build you a set of heads custom for this thing, mabey some preadators and have the valves moved a tad to help air flow with the smallish bore. Run as much compression as you fuel will allow.