Roller is not needed with zddp. Everyone says how affordable a roller is but it really isn't when you factor in pushrods, a more expensive than flat cam, more expensive lifters, and you might as well change the rockers too. I'll go roller when they finally make lifters as quiet as the stockers and I just don't think that's possible using a 109 block. Flat tappet cams are just as reliable with ZDDP. I haven't met a single person on this board that has wiped a flat tappet cam while using ZDDP regularly with ANY oil. Even if you do go roller, the ZDDP still benefits other components in the engine too, so if you should run it anyway, stay with a flat tappet. Most cam grinders reverse taper the #3 exhaust lobe now to promote the spin needed to preven wiping it as well.