[W126 Coupe] Advancing the timing on a 380

[Shayegan, Richard]

What are y'all's thoughts on advancing the timing on a 380 engine? My pal who makes funny cars (well, they're not funny cars, they're one step below I think, it's the one's that do straight line drag racing but are based on old muscle cars...but have over 800hp) tells me if the spec is 0 degrees at idle (it is) and it calls for 87 octane (it does) and I run 93 octane (I do), I could probably gain a good bit in the low end and stay the same in the upper end by advancing the timing 4 degrees or so. The guy who owns the shop where I take my car says maybe in the 60's, but with the timing computer in the 380 it does this automatically. He also says that advancing the timing is for top end and retarding is to get more power (vs. my funny car friend who says retarding increase top end at the expense of fuel and low end, while advancing increases bottom end while not harming top end). Who's right?
Richard