i recently just purchased a 94 z28 and one of the back springs is broke, so i need to buy a new set, or may as well buy all 4. Question is should i buy 1 inch lowering springs since i have to buy new springs anyways? I will eventually have full exhaust on the car including headers and im afraid they will scrape with the car being lowered an inch..im not sure?

 

whether they scrap or not will depend on the road conditions in your area...as well as the style and even brand of header you install.

if roads are smooth, and there are not many "peaks" in driveways in your area....you should be ok.

i'm sure with some searching on here, you could track down some stock springs for CHEAP....check ebay as well, and maybe www.ls1tech.com in thier "for sale" forum.

if you want to lower it, realize that alot more comes into play than just springs...at least to do it right

you'll need new shocks...if for no other reason than you have to pull the whole front end shock/spring assembly out to change the front shocks...why do that twice?
good shocks for a reasonable price would be strano revalves...$400+. you could get away with regular valved shocks, but the ride won't be as good as it can be. the high $$ option is Koni SA...about $850 for all 4.

to center the rear end you'll need an adjustable panhard bar

to keep the rear end geometry correct to prevent wheelhop under hard acceleration, you'll need some relocation brackets...$100 for weld-in, $130 for bolt in.

 

As you can see, it's probably not as easy or cheap like one might first think. But teke gives a nice break down of what is needed to do it correctly. Up side to this though, the car will handle much better. Oh and don't for a front end alignment.