Someone school me on them. Found some local for a fair deal with comp 1.7 roller rockers. They are the 1.9 valve, pedestal mount. They’d be going on an explorer motor with a comp xe258. I believe they have the factory springs still. Supposedly good for .575 lift but I have read they are & they aren’t. Cheap insurance I guess to replace them. Can factory stamped rockers be ran? Currently running 3 bar gt40 with Alex parts springs. Truck shifts around 5500.