The harmonic damper seal surface diameter for the SBF is 1.877” while the diameter at the seal surface for the Y is 1.875”. That 0.002” difference is just enough that the SBF sleeve may be loose on the Y damper. Going to the catalogue, I see where the harmonic damper repair sleeve for the Ford 272/292/312 engines would be the same repair sleeve as used for the Buick Olds Pontiac 4.3L & 4.9L engines and the 326, 350, 389, 400, 421, 428, & 455 Pontiacs. The small block Fords lists a different sleeve repair kit than that which is listed for the 292/312 engines.