I need more timing adjustment

Your dist. sort of has two timing adjustments, see the drawing. There's a slotted hole where it clamps to the dist. and one at the engine. If the combo of those two isn't enough, you'll have to pull the dist. and move the gear a tooth. But if it HAD been running and timed OK, I'd suspect something wrong -- light the dampener has slipped, or the timing chain has slipped.