I totally get that these cars were built to be low to the road for better performance, but the tail of my '76 seems to sit a little lower than the front.  I'm guessing it's probably due to tired shocks, springs, etc, but I was wondering if anyone has put bigger rims and/or tires on the back to help compensate for this, and if so, what impacts you may have noticed in the driving of the car?

I'm not really planning to enter this car in LeMans anytime soon, but just wanted to hear others' experiences.  Thanks!

Greetings,  It the car is all O.E.M., it is probably a weak sagging spring. Shocks don't hold a car up, they just dampen the movement from bumps.

Thanks for the quick reply-  I figured as much.

Are the wheel well gaps the same on the rear as the front? 

I will measure and report back.

The rear spring should be essentially flat when the car is unloaded. If it has a reversed upward curve that it has started to sag. You can compensate for this by putting longer spring bolts in on each end of the spring.