Best engine oil for 3sgte??

engine, synthetic, guys, miles, recommend, mess, wondering, change, 3sgte, redline, mt90, tranny, night, heard

Doing the first oil change for the 2, what oil should i go with?? I just did redline mt90 in the tranny last night and am wondering should i do synthetic in the engine as well? I heard somewhere that if u put synthetic oil into an engine that never had it, it could mess up the engine?? Idk, what u guys recommend? The car has 93k miles. Thanks