Depends on your application and how good the heads are. I know the little 360 I built for my truck had 114 lsa and while it didn't have a lot of peak power, it pulled from 900 rpm all the way to 6000 and had a flat even powerband the whole way. Now I'm not saying the heads were good, because they weren't, but for the application, it worked. Wider lobe separation with good heads will carry the rpm further but may not get there as fast depending on the rest of the combination. Large cubic inch engines tend to like more separation than smaller ones. For a road race car I think I would tend towards the wider end of the spectrum. If I remember correctly on the twin cam mercedes stuff I messed with, the exhaust camshaft had the variable gear on it. At lower rpm it would move to increase the separation for a smoother, cleaner idle, but in the midrange it would tighten up, then once it got past the higher end, it would widen up again to carry the rpm higher. One advantage to multiple cams or cams inside of cams like the new viper v10. I plan on running in the 111-112 range with my W9 headed 408 for my challenger, but it's primary purpose will be road courses so the rpm variance will be much wider. If I was setting it up for drag racing, I'd throw in 106-108 to pick up the peak power and match everything else to that power range. If you like a powerband that's flat, go wide, if you like steep climbing power that drops off quicker, go tighter. Keep in mind this is general rule of thumb, the entire package determines what cam timing events are needed and only lots of testing will get it where it needs to be.