what is the best oil weight for a 2000 carbed 500 HP

This is something that everyone seems to have an opinion on, and there have been several old threads that you might want to look up.

Personally, I have 500hp carbed engines, and I used to run the Mobil-1 15W-50. This year, I switched to the Mobil-1 20W-50 V-Twin Motorcycle oil, and the engines have run great and I have noticed to burn less oil than when I used the 15W-50. The 20W-50 is a little more expensive ($9/quart) and can sometimes be difficult to find, but I am a believer.

Anything with a 50 after the "W".

If you have a tendency to consume oil, the higher the number before the "W" the less oil you will consume.

Ken