I did not have to bush the lifter bores , but my block was not drilled to feed the lifters.
I used the drill fixture sold by MoPar to drill into the oil galleys , but their recommendation of a 3/16th hole struck me as way too much.
I used the drill fixture as a pilot for a #2 starter drill and once I had the holes located , used a 3/32nd drill to finish. ( .09375 )
That is probably still too large , but was the smallest drill bit I was comfortable using with a hand held drill.