I just had my camaro for almost 3 months now. I never did the suspension on it. The only thing I did was get brand new tires. And I believe my brakes need to be changed. What can I do to eliminate that bad shake after I speed over 70 mph on the highway?

 

Get your driveshaft balanced or replaced. Then your wheels if not already done. Then have your rotors cut and put new pads on.

 

Do you mean as in balancing the wheels?
If so, I wont do it until I get my suspension done, not to mention the brakes as well. Thanks for the suggestion

 

Either buy an aluminum driveshaft, or take your current one to a speedshop and have them balance it. I've taken my aluminum one to 140mph and no shakes with that one.

Once you get the driveshaft taken care of, then balance your wheels. Unless you are changing tires very shortly, I see no reason to "wait until the suspension is finished" to get your wheels balanced.

Also check your tie rod ends. My buddy had the same problem and it turned out to be one of his tie rod ends had a slight amount of play in it, but enough to cause a vibration at speed (THIS is dangerous).

Another obvious one is to make sure your lug nuts are all torqued correctly, as well as any other parts of the suspension/steering, though I'm still blaming the steel driveshaft the most...followed by the wheels.

 

About the lug nuts, Im missing four because the missing four were locks. And I didnt have the correct key for the locks. But my wheels have new tires.

 

If you just got new tires, I'm sure the wheels were balanced at the same time. One missing lugnut per wheel won't kill you, but go to Pep Boys or wherever and put the last 4 on. The vibration is probably the driveshaft. Go get it balanced or replaced.