I have a 69 with stock suspension. Thinking of converting to coil overs. Has anyone used coil overs with stock control arms? I have read some horror stories online of guys who have installed coil overs and the shock shaft bending.
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.
Bluebird, My current front suspension is completely original. I am going to change from drum to disc brakes in front. At same time I wanted to lower front end so in was thinking of using lowering spindles. As I will have front end apart I thought that I should also replace turbulent coil springs at same time. My passenger side could spring has rubber spring blocks in it. Driver side does not. Not sure why but car sits perfectly level. Thought using coil overs would be easy button to both set ride height and refresh suspension. Ideally new tubular control arms would be nice but car is used just for cruising and tubular control arms are quite expensive and not in budget right now.
Hmmm, you'd think if one spring was sagging they both would. Adjustable coils may help with that. You can get true coilovers that have the bottom and top of the spring attached to the shock [like a strut] or the ones I have that have the top of the spring going into the original spring pocket. I know a couple others on this site have them, I think Quick68bird has them on his car and by the look of the pics he has the stance lowered a bit, looks nice. You should weigh the car at the front wheels and the rear wheels, with and without driver and passenger then use that info to get the spring rate you need. I got a set of QA1 coilovers part number GS401-10450A from Amazon. They shipped to Pender Island for free and cost me less than half what they would have from anyone else. You may not need the 450 pound springs. Do some asking around and check the weight of your car. I went to a waste company that weighs the truck before and after picking up yard waste, he brought the scales to my place and weighed the car while we had a case of beer. I got the numbers for empty car, driver only and driver and passenger at all four wheels.
What did it weigh Al? Mine went 3500 the other day when I had it done. No driver/ 1/4 tank of gas. I had the front, then the whole thing and then the rears. Got it written down in the car.
I went with the QA1 coil overs and stock control arms. Setting ride height was really easy and ride feels great. Disc brake conversion was also definitely worth it.