Hey Mike V,
Nothing wrong with technical stuff

For the LSA, that was a misleading statement on my part. Thanks for pointing that out. What I should have said, for a 4.8 and a fairly aggressive cam, is to keep it around 114 LSA.

As for where I got that, it was based on correspondence with Allen Nelson (Nelson Performance) and Dave Tuschhoff (Thunder Racing). That "rule of thumb" LSA value for the 4.8L is to keep a good idle and drivability for something like a 212/218. I'm sure you could go to a little more aggressive cam w/ the 4.8, but in an otherwise stock engine, things might get pretty tough.

As example, Thunder has a 214/220 .600/.523 115 LSA custom grind that would be just fine in a 5.3, but in a 4.8 may have disappointing results. Same could be said for a 112 LSA and 220/224 duration one.

Whatever the case, long tube (or at least mid-length) headers, a higher stall, upgraded springs and good tune are in order; unless the cam is very mild, and what's the point of doing that