I run a 104 in my 383W, but it has almost 13:1 compression and a 5000+ stall converter.

I ran a 106 for a while with the same compression and a 4200 converter and it worked well.

Don't really know what efffect it has on idle. Mine will idel in gear at 900 rpm when warmed up. Powerband is pretty wide. comes in around 2500 and pulls very hard all the way to 65-6600. It will rev all the way to 7200 easily, but is shifted at 6800 for consistency.

Later,

Within reasonable limits, a tighter lobe seperation angle makes the power range narrower, but larger. Tighter lobe seperation angles generally produce more peak power. Narrowing the lobe seperation angle also moves the power band LOWER in the rpm range.

A 244/254 cam with a 106 LSA will make more power, and make it earlier than an otherwise identical cam with a 114 LSA. However, the 114 cam will idle cleaner and pull more smoothly off idle than the more punchy 106. It will also RPM higher than the 106.

Tighter lobe seperaton angles also produce really choppy idles that most of us like.

Most drag race cams are around 104-108, while street cars generally use 110-114 lobe seperation angles. For hot street cars, I generally like somewhere between 106-110, unless they rely on nitrous or a blower, then wider can be better.

As far as advancing or retarding a cam that's already been ground... Advancing it generally moves the power lower in the rpm range, while retarding the cam (within limits) moves it higher up the scale.

This is really just the basics... but enough to get you in trouble.

Good Luck!