A 292 has a damper. From the front it does look like a solid pulley but there is a damping mass behind the pulley, you know what, here:

Stock dampers left and right. You see the belt groove, then a small gap, then the damping mass, on which are the timing marks. Notice how the gap on the rusty one is wider? That one has probably slipped.
If your engine truly has no damper, then it could very well be a 239, which could explain the lack of power. Though If the late model distributor fit it's probably not a 239. It would be worthwhile to check the distributors advance curve, though it's probably not any worse than stock. Definitely do not assume.
Lawrenceville, GA