Does a plymouth 360 cu.in engine need special pushrods with roller rockers?

I have been offererd a set of roller rockers for a 360 cu.in. plymouth engine but my present pushrods are different, do i have to buy one of these 'make them yourself. kits or are there aftermarket ones avalable? i have searched around the internet & all i can find is replacement original type, where i need ones with a mushroom type end where the rocker arm sits, any help from you american car fans would be appreciated