Bingo on this thread. I have a running but pos 235 that I would like to hop up with a rebuild. I'm am asking about the potential of going bigger bore and with premium pistons, mildish cam, port/polish heads, big valves, etc. Will this motor run on premium unleaded if the compression is jumped to, say, 8.5:1? Do you guys consider fuel injection as option for the 235 or too expensive? I am reseaching the idea of keeping my old motor over the v8 or 261 option. At least now I see a few folks upgrading the 235, so it can be done. Why don't you guys go to the 261 (full flow) as it was recommended by others to me?