The 700r won't need the much gear a 3:42 will be more then plenty. When look for a cam One other thing to be looking at Is the Lobe seperation stay with a 112-114 lobe seperation It will give you a smoother idle that your after (110 at min.) anything less will start to give you a rougher idle.If you still wanted it to look like the stock 230 Go with the 250 block. Yes the 292 would be more bang for the buck. But you would end up with better MPGs out of the smaller cubes over the 292. With the same Mods. The head is one thing you realy need to look at No matter which motor you use. stay with the stock size valves a good 3-4 angle valve job New springs and have a set of Lump ports added along with Dual exhaust.
If plaining on running a tri carb settup it would look Hot yes. Set that up with a progressive type linkage so the at idle your mainly running off one carb and at cruiseing you can be running with the others. Hope this helps }[oooooo]