The paths diverge.
The 235 is more popular, cheaper, more spares available, fits cars up to 1962.
The GMC (at least the 270 and 302) have more potential, good position for XO with a 325" limit. No auto installs without mods.
The lower ends are almost identical as to design and function, but the heads are completely different.
We still have no clues on a possible 235 "hybrid" head. Santucci had a running start because both the 292 and SBC have the same bore pitch.
IMHO there is still no market volume for complex $$$ speed equipment (there is still no Ford 300 alloy head), few owners have that big a hit in their budget.
A modified 235 can be much faster, certainly faster than the mods of 1955, but the car is still not fast compared o street cars today.
The 235 cam is too close to the rod path to make the rod or stroke much longer (the 250, 292 cam is moved out of the way).
What would you buy if available?
