1. No
2. No, will require modifications to fit.
3. Yes, stays cooler.
4. Yes milling the heads is a problem. Valve to piston clearance & chains.
5. Not I
6. Only "known" upgrade is the SVT profiles.
7. Something noticeable.

2000 SVT #674 - Check it out!

Whoever coined the phrase; "If it ain't broke; don't fix it" ~ Just doesn't get it...