Modern cars run higher temps for emissions purposes, not efficiency. For example the fans on a Camaro / Firebird come on about 220-230 range. Check the thermostat that you have. If you are using factory gauges, remember that GM only paid $1.45 for the air core in the temp gauge and are not that accurate due to variances in the air core thermister, the gauge sensor, quality of wiring, ambient temperature and battery voltage.
First I would verify your reading is correct. I found a good infared thermometer is handy for verifying temperatures. If you mixed brand a gauge and brand b sensor, you could have a resistance / thermister miss-match resulting in incorrect readings. The actual coolant point should be the modulating range of your thermostat.
If you truly have a cooling issue and do not have a fan shroud, start there as you are probably checking the temp with the engine sitting and there is no air movement through the radiator. the fan should be able to hold a piece of heavy cardboard to the radiator by itself. Fan blade to shroud clearance should be as minimum as possible. Fan spacing from radiator should be no less than half the hub diameter. Since the V6 is much shorter than the inline 6 you pulled out, you will need to go to a long shroud if you want to keep the engine driven fan. An engine driven fan will always out perform electric as the best single fan will only move 2900CFM at 0" of static. However with the short motor you may be forced to electric fans.
