I bought a 74 Duster from a guy in 2007. It wasn't running when I got it.
After fixing it up to sell, I drove it around awhile to sort out the usual squeaks and rattles. The 318 was quiet, didn't smoke and had great oil pressure but was an absolute slug. It wouldn't even peel out in gravel. I tried more ignition timing, different carbs, distributors, coils....THEN I had the idea to pull the timing cover for a look-see. Someone had replaced the timing chain yet installed in T H R E E teeth off the mark, retarded. That is over 24 degrees! The 8.0 compression saved me from valve interference. I clocked the cam sprocket and screwed it all back together. The car easily smoked the peg leg tire after that.
Cam timing really makes a difference.