If you want to stick with a 235 you could put a late 261 head on it and that would drop the compression to about 6.5:1 or so, plenty conservative for a blower. A 261 is a good choice since the oil system and cooling is better (full flow filter and bypass thermostat) and the compression is 7:1 stock. A 261 will drop in replace any 235. As long as you keep the RPM's down below 4500 and are careful about how you drive the blower I don't think a 235 or 261 or GMC 302 would have a bearing problem as long as you were careful about setting up the system. Use a good harmonic balancer though.
