would i have to replace the driveshaft for a heavyer duty one with a high HP engine? lets say 550HP engine? or would a stock drive shaft work just fine?
i dont want to have a weak link somewhere.

I have not run 550 HP in one of these cars, to get that issue out of the way at the beginning.

That being said, in similar weight cars, I have not had to change the driveshaft. I did run heavy duty spicer u-joints. The u-joint is the weak link in your chain. That is why you need a driveshaft loop. When you break a u-joint you won't pogo your car or tear a bunch of stuff up.

I only had new heavy driveshafts made for my off road trucks. That was not because of the engine, but with low gears, meaty tires and good torque output, a clutch drop has shredded a few shafts in my time. There really is no weight on the back end of our cars, so usually the power causes the tires to break loose. If you put an engine in your back hatch and then did a clutch drop, you MIGHT break your shaft.

If you're really worried about it, you can pick up a stout one from Spohn, a sponsor here on the site. They offer the "Top Gun" and "Extreme Duty" driveshafts for our cars. They're pricey though ($350-$450 range).

i'm running an extreme duty from spohn.. only about 475hp but it'll last me forever..