Always. If you are under 260ish on the seat it’s probably ok if you are using iron rockers with a hardened shim in there. With aluminum it’s gets worse. Once you go over that you need a Torrington bearing in there or it will just keep eating the rockers and making a mess.
I narrow the exhaust rockers and put a bearing on each side of it. I’ve been over 340 on the seat and it’s a must at that level. If not, it eats power like the hamburgerler on a Micky D’s nasty burger. And junks the rockers.
