I was thinking about putting on a set of bilstein shocks on my car and I'm not sure if I should go with the sports or the heavy duty's. I have heard that sports are softer and for lowered cars, which mine isn't. Which do you think would be better for my car and why? Thanks.

 

I have HDs on the back of my car.
These statements are repeating what I have read here. I have nopersonal experience with the "Sports".
That said, the Sports are supposedly the same valving as the HDs. They are about 1" short fully extended, so shorter springs do not become so loose (or Maybe dis-lodged) when your car is lifted in the air.
A while back someone was looking for Sports, to little avail. It was stated they were very hard to find.
My experience with my rear shocks is quite satisfactory. I do not think you will be disappointed.
One last thing. Coil overs will NOT work with Bilstein struts. Any kit I have looked at says that, upfront.

 

So would I have to get the hd's since the sports are made for lowered cars, or would they still work on my car? Also, is it true that the hd's are stiffer?

 

Try the search function. In THEORY, you should be able to find discussions on this subject.
My understanding was you want the HDs. I also think they are no stiffer than the Sports. I have read comments that the Koni Yellows are a good bit stiffer than the Bs. Those Konis are the ones much praised here... if you can stand the stiffness.
The HDs should be acceptable.

 

Im not sure on which ones I want. I did use the search function at first and didn't find what I was looking for.

 

I too had the same question. I once tried contacting the Bilstein distributors in Canada to ask this question. They did not respond to my e-mail. You may want to try them as well and post your response. Summit Racing lists both the rear sport and heavy duty as fitting firebirds.