I don't know a lot but here goes:
The 4.5 I don't know, depends on if that's dished or domes
The 10.5 is compression ratio. If you want to go FI then you want something much lower, usually 8.5 or or 9:1 is what most people go with.
Dished, flat top, and domed pistons are the type of piston. Imagine concave, flat, and convex type if that puts it similar.
Sold - Black 2000 Mustang GT, gone but definitely not forgotten
- Silver 2007 Corvette
Current - DHG 2001 Bullitt