When I first got my 98z28 I ran it at speed and it handled fine, mine did not have any rev limiter, I went to 5700-5900 or so in 5th, after that it wouldn't pull, I also tried 6th gear and it wouldn't pull much, 5th was better to go high speed.

I would think the limit of a stock LS1 would be in the mid 160's. Going 200 would be cool in a car, it's easy on a bike. Who all has gone 200?

 

http://www.f-body.org/gears/

A 3.08 gear in an M6 would just barely get you there in 5th. Out of our more commonly used gears you would have to use a 2.73 which would be more than enough. It takes a lot of power to go 200+, especially with less than ideal aerodynamics. As speed increases, wind resistance increases by twice as much. I've never done more than 155 in any car, but 200 would surely be a rush.

 

I had a buddy of mine (state trooper) clock me at 175 on a 5 mile strech. 98ss m6 3.73 in 5th w/ speed limiter removed and a few other things, but I think 200 is do able... just dont try and turn. My car was floating w/ suspension mods.