69 Barracuda Clutch Shake Help Needed.

I know he said the flywheel was resurfaced, but... I've heard of and experienced the "1st gear shudder" several times, and the cause was always (IIRC) the flywheel needed resurfacing, and for whatever reason wasn't.

I won't install a new clutch anymore without a resurface, just won't do it.

I do remember an occasion where motor mounts aggravated the situation, but the root cause was flywheel surface.

I'd have the flywheel surface checked, or swap the flywheel if an alternate was avail, and or check flywheel runout while it's mounted on the crank.

hope it helps..