Your best bet is to mount the flywheel or flex plate and jam a pry bar into the ring gear teeth and whatever you can wedge it against. If you can get a good bite on that the crank pulley bolt
will break loose... trying to jam the harmonic balancer will damage it.
SHORT BED 4-DOOR DIESEL: 1986 F350 4x4 under construction-- 7.3 IDIT ZF5+GVOD
STRAIGHT SIX 4X4: 1981 F150 2wd to 4x4-- 300 I6 close ratio diesel T19, hydroboost brakes, Saginaw steering
BIG F: 1995 F-Superduty under construction— converting to 6.9L IDI diesel ZF5+DNE2