Those Indy rockers --made by Dove have always been sold by Indy as the rocker--Indy KNOWS that they can't handle roller spring pressures or high spring pressures for long---You have experienced the same failure that hundreds of Indy customers have seen over the years--they run for a while but then--K Boom You use them on a street solid cam and they may last forever--use them in a serious race unit and well.....
Hughes, Harlands, Jesels, etc for real race engines
BTW I have never seen an Indy small block rocker do that but I have seen dozens of the BB units fail--replace the entire set now or risk future destruction