Two years ago when looking at cams and lifters I asked Comp cams and was told they didn't recamend rollers in street driven FEs. They said that the little needle bearing in the rollers would not get enough
oil to survive.They had a limitted life expendency.You had to replace or have the rollers rebuilt. Like a spare set of roller lifters was the normal thing to have .Shame on you if you let them go too long .The rollers would come appart and metal went everywhere in your motor. As I understood it, the rollers got their
oil thrown up from the crank. If someone could get pressureized
oil from the lifter gallery to the roller needle bearings they might last longer.
Remember I'm talking about a street driven car not an all out racer with a quick change engine.Changing the cam shaft is an ordeal, let alone a bunch of metal through out my engine. Releiabillity is a major concern for me.