C3 engine control system and A/C and engine were all faulty when first purchased. Engine was replaced with remanufactured Jasper engine (for $1500) at about 110,000 miles.
A/C not functional when I bought car (for $2500, car body & enterior were near flawless) but repaired and retroed to 134A.
C3 system was unstable (does what it is intended to do... be stingy with the gas!) so it was replaced.
Underwent a major project where the C3 system was scraped in favor of Edelbrock Performer Package (carb, cam, intake manifold, double roller timing chain) w/Edelbrock Signature Series valve covers, air cleaner, & Mallory vac. advance distributor w/ ign box & coil.
Car runs strong for a V6, but gets only 8-12 mpg, (carb may be running rich). Silver/gray with cream top & Cragar S/S wheels, BF Goodrich T/A tires. If 4-door GN existed, it might look like this.
You should have gotten rid of that V6 and installed a 307, or possibly and Oldsmobile 350. Even the little 260 V8 would be better than the V6.