Just have to ask, why do you want coil-overs? If you are doing different types of racing and also some cruising, I can see having the flexibility of adjusting the height and ride of the car. Or if, like me, you just can't get the ride height correct due to a worn out or badly repaired front end the adjustable coil-overs may help. Some people buy the aftermarket stuff and install it in there cars because they believe all the hype from the manufacturer's, better performance, more power, thicker hair, whiter teeth etc. I've had the control arms off my car at least half a dozen times and have changed out springs with different lengths and rates six times as well. No matter what I did I could not get the tire rub to stop without having the front end way too high. I finally aligned the front with a different than stock numbers and installed a new set of control arms. The rubbing stopped but the front was a little high. I took the recommended 1/2 inch off the springs to drop it 1 inch but the front end dropped almost 2 inches, now it sits too low. I bought a set of adjustable coil-overs as I never want to take the front end apart again. Although I've had them for five months I haven't installed them yet, I just can't convince my back and shoulder they won't hurt afterwards. I bought the type that has the upper spring fit into the original spring pocket as I didn't know about putting all the front end weight on the shock mount instead of the spring pocket. The shock mount may take the weight without any damage but...? Something like having rear air shocks, the weight of the car starts to ride on the shock mounts not the spring mounts. As my lower arms are not made for coil-overs I will have to weld some support in before mounting the shocks. I can't tell you of any hands on experience with the coilovers but maybe a few things to consider before you switch. There are plenty of Firebirds out there that run just fine with stock parts, I'd be willing to bet a lot better than some of those with aftermarket parts.
