Oil Changes

What do you guy's think my oil change schedule should be if I use synthetic oil instead of regular? 1988 Delta 88 olds 3.8L V6.

I used to change my oil every 3000 miles and use a napa gold oil filter.

Currently I am going 6000 miles on the synthetic and filter. I am using Mobil 1 Extended Performance.

Do you think it is too long of an interval between oil changes. I am a long distance driver.

No! With dyno oil the oil change interval needs to be more frequent. With synthetic oil that does not break down then the doubling of the interval is not a problem.