1.5 vs 1.6 rockers

Can't say if this has any value for a V-8, but some slant six racers (not me) have done back to back at the track on the same day, comparing 1.5 stock rockers to 1.6 roller rockers, and reported little to no gain. It seems like the benefit of roller rockers on a slant, is consistent ratio, and strength for a full boggie high revin engine.

PS: on the type of engines I build, I can think of better ways to spend $1000 (like another complete engine). It is less expensive to change the cam, and can get bigger gains.