The weight of the crank and rods in a 292 is far heavier than in the 250. Use the 292 balancer on the 292. You may need to shim your water pump pulley, alternator etc if you do not have the 292 pieces, but it beats the heck out of randomly needing to tighten the flywheel or flexplate bolts.
For grins, it might be interesting to know the weight differences between the two balancers.
