Yeah, it is probably the timing gear. Don't sweat the crank unless
it has been horribly abused. They ALL wipe out timing gears unless
yours is steel. I have one engine I have put together twice (in different
blocks) with the same bearings. Still shows good oil pressure 15 years
later in spite of having been run for 10 years dumping most of the oil
through a bad seal in the main oil line. I pulled my B30 after 204,000
miles suspecting a lower end problem, and replaced it with another engine.
When I tore the old one down it had NO measureable wear on mains or rod
bearings - plastigaged like new. The noise was - you guessed it - the
same old timing gear!

So pull your timing cover and get that fershlugginer fiber timing gear
OUTTA there! Probably loose on the steel hub. I understand that NAPA
can get you an aluminum timing gear for around $140. Bound to be better
than the fiber one, which was used on the B16, B18, B20 and B30, and
maybe even on the B14.
--
George Downs Bartlesville, Oklahoma