Roller cam swap in 1991 360

I have what I guess you could call a nos 1991 360. It's got zero miles and its never even been started. Now here is the problem I have. I wanted to put a comp cam in it to butch it up a bit. Stock hp is only 190. However, comp cams says I can not use the factory vavle springs. These engines have different springs for exhaust and intake as well as different lock groove locations on the valves. Plus two different types of retainers. It sounds like I'm going to have to do the whole damn engine over just to put a cam in. Is this really the case or is comp cams just trying to hose me? I figure someone on here has to have gone through the same bs with one of these pre-magnums. The engine needs to go in a car soon so any and all advice is welcome.