The first time I removed and replaced the front springs, it took a day and a half. The second time, it took about 4 hours. It helps to have a lift, two people, and a transmission jack. We used the jack to support the control arm while we took things apart, then gently lowered it until the spring popped out. I really wouldn't want to do the job without a lift. Be careful under there, the spring is powerful.
You should watch the video Dick Mentzer made of Jim Villers' seminar on how to do this. It was taped at the Blacklick gathering in 2004. (Pagoda University - Blacklick) He does not follow the procedure in the BBB. We followed his procedure and it worked really well. Just for giggles next time we're going to try it by the book to see which is worse.
Absolutely have all new rubber. Cox racing sells a polyurethane kit that I will install when I get a chance. That should stiffen things up even more than the sport springs and Koni shocks already have.
In addition the new spring pads for the front come in four sizes and the rear come in three. Ride height is affected by small changes. I found that the ride height on the stiffer springs was too high even with the thinnest spring rubbers made. If your ride height turns out to be too low, you can make up the thickness of the pads with flange gaskets.
I highly recommend the Koni Classic adjustable shocks while you're doing it. Use them at mid-range for sport linear springs and a half turn stiffer for progressive springs.
This is an experimental hobby. You may have to make a change, drive it for a while and make a different change. There are a lot of opportunities to tweak the handling. The good news is that after you do it once or twice, you'll be an expert and nothing about the steering or suspension will scare you.
The video is on DVD and is worth the effort to find and watch. I don't know if it's posted somewhere but there are details that the quality of internet video won't show you. E-mail me if you can't find a copy near you. (Naj, do you have a copy?)
Ray
'68 280SL 4-spd Coupe