had a used engine put in my 2002 GP. left the shop. now when I go left or straight, it sounds like a truck, took it back 5 times, they kept saying number 6 spark plug ( which was changed 3 times. only time it isn't loud is when I turn right. currently it's louder! was told could be wheel bearings need greasing, have you ever heard of this?

Not sure of the engine, but this does sound like a bad wheel bearing, The right bearing is probably bad because you said the noise goes away when you turn right, but get louder if you turn left this is because when you turn right most of the weight of the car actually goes to the left, so when you turn left more of the weight is on the right side of the car making the noise, Just replaced mine in my 98 Grand Prix with the same problem as you just without the engine being replaced, I did the wheel bearings myself and saved a ton of money, exhaust leak and engine problem are also a possibility although this seems to be wheel bearings to me.

Yea however told you that they needed grease must not know that the Grand Prix have to buy new hub assemblies not just bearings, got both of mine for about $140, but I bought performance bearings which are a little more.

It sounds like maybe a plastic shield or cover in the vicinity of one of the front wheels is rubbing against the tire when you drive. Get underneath, with a light if its dark, and have a look around. All those plastic shields and guards were probably off during the engine swap and its easy for one to get put in wrong, or to come loose.