When taking the 4.3 motor mounts off, and installing the 4.8/5.3 mounts, is there any cutting, grinding, or welding that needs to take place? Or is it simply bolts only?

I have some questions about the fuel lines, but Ill wait to get some pictures up. Well I'll just explain it first without the pictures, and if its still unclear, then I will post pictures. I have the COMPLETE fuel rail assembly from front to back from a 2001 Ext Cab 5.3. Will anyone of this work. When I mean complete, I mean I got it from the dealership for like $230 bucks.

Lastly, on a scale of 1-10. How hard is the swap from a 4.3 to a 5.3?