I too have a 79 w/sbc, but it has iron heads. I used drag springs in the rear w/1 inch spacers to raise the rear fenders just above the 275-60/15 drag radials. So it sits slightly lower in the rear.
I completely rebuilt the stock front end, even using the stock springs, but incorporated adjustable 90/10, 60/40, 50/50 Summit shocks. Also put an alum radiator in it. With the steel heads and hood, it sits lower than yours, with the front fenders sitting just above the 245/60-15 tires up front. I thought it sat too high (about where yours sits now) until I installed the engine and trans.
Dunno how much a glass hood weighs vs the stock steel hood, but that and still retaining the power steering may be the difference. This setup with the stock 305 and th350 (very tired), the 60ft times were pretty bad, but the suspension worked as expected with the 90/10s keeping the launch lift where I expected it to be with a no-torque engine...waiting to finish the 350/350 engine/trans install to try it out this fall.
