Having recently registered my car, I now have a chance to iron out any little issues.
One problem seems to be that I either need stiffer springs or to upgrade to shocks with more high-speed compression damping control.

I have around 4.5" between the top of the 29" tall tire and the wheel tub, which I thought would be plenty of clearance. It was no problem with an almost empty fuel tank, but putting 15 gallons in there has meant that the passengers rear tire hits the top of the tub on seemingly small bumps. It feels like the car barely moves over the bump, but it just punches the rear end up in a split second.

If you can recall, how much clearance are you running from top of tire to top of wheel tub?
Spring rate/weight?

I would also ask in Pro-Touring, but I wonder if the rates would be different due to the pro-street cars having their springs so much closer together...

I figure the rear springs and shocks are the cheapest part of this car, so I'm happy to go with some proper coil-overs - just not sure what I should be ordering.

http://i868.photobucket.com/albums/ab244/randompicsofstuff/Pro%20Street%20Yenko%2068%20Chevelle/IMG_0284.jpg

http://i868.photobucket.com/albums/ab244/randompicsofstuff/Pro%20Street%20Yenko%2068%20Chevelle/Chevelle.jpg

Thanks for any assistance,

Craig

Mine is strictly a drag car, so I would think maybe a little stiffer would help. But mine weighs 3160 and I run 130 lbs springs. I would think like 175 might work for yours on the street .

Thanks Ray. Great launch photo in your link!

It seems the pro touring guys are using 175 to 200 in the rear, so 175 with the bigger sidewalls and more relaxed cornering requirements would seem to make sense...

I've lifted the car a little more in the rear for clearance, plus I'll fit some decent shocks that have some adjustment. The old shocks in mine look like they've been around since the car rolled off the showroom floor!