I agree with Charley, the biggest difference between the two cars is the exhaust. There are numerous other differences, ie; pistons, combustion chamber, etc... but the exhaust is the biggie.
I have a Gardner system on mine, the stock system not the deep tone version, so I have 2.25 inch pipes - crinkle bent, two resonators, single crossflow muffler with two-in two-out, and 2.0 inch tailpipes. Neal had installed the pure stock allowable 2.5 inch mandrel bent system with flowmaster mufflers. Better breathing! I knew the differences, and also knew the cars would be close after Frankie put the 3.73's in the rear and took out Neal's 4.56's. It was a fun, close racing.
I have Pete's copo Nova setup in my carb, approx. 38-40 degrees of timeing all in by 2500 rpm, and 40 psi in the rears, 45psi in the fronts. I couldn't run my spring clamps because they were interfering with the frame rails, and the bolts had too much of a shoulder on them and therefore would not tighten up. My fault, I should have installed them before the day of the race! Better yet, I should have called Neal to have him make me set like he put on Frankies car! I would either bog or hop, frustrating, but... that's racing
BTW, the CR's are probably a lot closer than I originally thought after talking to Rob and Pete - again, my fault for using TRW's
Frankie was smart not to mess with Neal's setup! I believe Neal raced that car in the Hemmings race at Lebanon raceway last year, he said it was in the 13.80's - right on schedule!