Why would a 1995 Corvette LT-1 emit white smoke on start-up and idle rough?

White smoke is usually caused by water in the ignition system(blown head gasket or water in the gas tank due to condensation. If it clears up after running for a while, you should try a gas conditioner in your fuel tank. If its constent, then do a compression test and to check your head gasket. White smoke is water; Blue smoke is oil; and black smoke is flooding or too much gas. ADDED NOTE: I have had an occurence where a brake fluid leak(at the master cylinder) allowed the vaccuum operated BRAKE BOOSTER to suck in fluid into the intake manifold, causing WHITE SMOKE..