rad valve stands for ,,,release at dumpster ,, v2 stands for ,,,victory 2owner,,, every reed block that i have tried with every set of reed pedal setup nothing has given me the great results as the v2s ,,,, i think i have worn out the intake bolts trying diffrent reeds ,, my buddy helping me and the key pad saying.... stick with v2s,,,,i think the v2 reeds larger tip surface area is what makes it hard to beat,,, i tried reeds every way and design came to 1 conclusion the v2 was the standard i could not make close to the same power with any thing else ,, they are a real advantage,,,they are not a gimmick