I have ALWAYS done that, but I do it after the engine is in and wired. The time to find out you have an electrical gremlin is now, not when you start the engine for the first time. I put in the battery and test everything; all lights, instruments, turn signals, horn, heater/AC fan, etc. If there is a problem, fix it now. You could have a wiring problem that could cause a smoldering wire or fire. Very unlikely I admit, but check it now. Do you know how to test your instruments? You'll want to know for sure your oil pressure and temp gauges are working BEFORE you start the engine. When you do these electrical tests (and when you start the engine for the first time), HAVE A FIRE EXTINGUISHER HANDY!!!!
