Weight reduction: Running out of ideas.

Shipping weight for a 1976 Corvette was 3445, curb weight was 3541. Add 200 lbs for a/c, th400, telescoping steering wheel, power windows, power steering, am/fm radio (18lbs for the radio!)
I'm just under 3200 lbs (3160) with a full tank of fuel (I'm supposed to be 3200 for the class I run in) - with 3 gallons it'd be roughly 3060... which makes your weight even more impressive.
That said, my weight bias is almost exactly 50/50 (within 5 lbs)
One of my scales died, so weighing hasn't happened recently - but once resolved I'll see where I'm at now. I suspect I weigh more

*link https://corvettestory.com/specs/1976-Corvette-specs-options.php
Had a spa/mental-health day today, roaming my favorite junkyard. Looked around for parts for a few project cars. Was surprised to find another C4 (an '85) in the yard. Last time I was there I pulled some parts off an '89 C4. I checked dozens of GM intermediate size cars looking for 11.5" solid rear rotors, but kept striking out. Close to closing time I stumbled upon an '11 Buick Regal with 11.5" rotors. The quick measurements I made (and comparing them to the rear rotors on the '85 C4) indicate a good possibility of trying them on my car. The only measurement that looks to be a concern is the center hole. The Buick rotor "looks" like it's maybe .100-.150" smaller. Right now the plan is to stop in there again next week, pull the rear calipers off the Buick and the C4 , and see if the rotors are interchangeable on the spindle/hub or not. I'll also bring my portable scale to measure the weight difference between these two rotors to see if the swap is worth the expense of new rotors and a machining fee.
Well, scratch the rotor swap idea for reduced weight. Went to the junkyard today and pulled rear rotors off an '11 Buick Regal and an '85 Corvette. The Corvette had drilled aftermarket rotors, and some wear, but the Buick rotors had similar wear. I weighed them both with my HF hanging scale, and the Corvette rotors were about two ounces LIGHTER (.12#). Weighed them three times, and the results were repeatable. So, this economical option isn't going to work.

While wandering around looking at radiator sizes and shapes for my street rod truck project, I saw some small radiators that might package in the rear of my '69. In addition to trying to reduce mass in my car, I keep looking for ideas on how to move some of the remaining mass either to the right or to the rear. I keep entertaining ideas on how to reduce the radiator size and weight (and airflow) up front, and move some of the weight and work rearward. Would definitely take some duct work and plumbing to direct the fluids, pretty sure that's doable, but I have no experience on what it takes to pump the coolant in that long of a round trip. I suspect the overall weight of the cooling system would increase slightly, but possibly a better f/r weight balance (currently about 1400/1300 pounds) might net a better handling car. As I heard someone once say, you can only go around a corner as fast as the slowest axle/half of your car.

Just trying to figure out a next move.