Smoke from back center of engine bay
 

Last night i drove from maryland to new york and was averaging about 75-80 the whole way, once and a while i would go up to 90 and for about a 1 min stretch i went 100mph. Mind you i drove the whole distance without stopping. When i got home whiteish smoke was coming from the back center of the engine bay.

I recently just had my tranny replaced, i babied the heck out of it for the first 1500 not going above 70. I never floor the car, and the problem doens't come around when i stay at 70-75.

Now i know the easy answer is if the problem occurs when you go that fast, DON"T DO IT. Still it shouldn't be happening. For this kind of car a 100 mph stint once in a blue moon shouldn't be that big of a deal.

I originally that it was coming from the right or left hand side of the engine, but now i think it might be the tranny.

Any thoughts or suggestions would be greatly appreciated. Thanks in advance

A lot of people have been having power steering fluid leeks recently. I'm one of them. In the back passenger side of the engine compartment, check your high pressure power steering hose and return hose.
Another obvious thing to check would be that all dipsticks are in place and firm. The ones for the tranny, diff, and engine.

Davie is correct. Add to this, however, the OE tranny cooler lines. Give them a check and make sure the clamps haven't loosened up since your install. Also, make sure they replaced the old style clamps with good ol' faithful worm-gear clamps.