My late 40s 248ci Eight stumbles and "misses" at wide throttle but performs and accelerates adequately after backing-off some. Does it in all 3 manual gears. New wires, plugs, condenser, and coil with timing set to 4 BTDC at low idle. Vac adv holds vacuum and moves the plate. I'm thinking perhaps sticking dist. weights or insufficient fuel pressure to match the WOT air stream. Curious as to others' thoughts.