Rhoads lifters

Honestly, I didn't know much about these lifters except that they used to be popular..I like to be different when I went old skool on my ride, I bought some NOS ones on ebay and they were probably close to 30 years old complete with the vintage box...I went with an old skool Isky cam grind and the combo works good, idles great and awesome power band, still pulls hard at 6,500 but that's where I have the rev limiter set at...might pull even more but not sure I need too and nervous about the "Boom" factor lol