The 292 should have a 2-piece lip seal that rolls out and back in pretty easily by simply removing the rear main bearing cap and loosening the other caps a couple of turns of the bolts to let the crankshaft drop a few thousandths of an inch. Some manuals reccomend staggering the parting line of the seal a little, rolling it about 1/4" off-center with the bearing cap parting line to prevent a leak where the cap meets the block. Retorque the main bearings, reinstall the oil pan, and you're good to go.
Jerry