Have a look again Fred... there's 4 of 'em.
Hi Jim,
the photos show that on each side of the shaft you replaced a full width roller race with two ball races.
So yeah, there's four of 'em.
A roller race is maybe four times as strong as a same-size ball race.
Each original full length roller bearing is WAY stronger than two propriatory roller bearings
which in turn are WAY stronger than the same-size ball bearings.