I have a Vortex rear sprocket on my 98 (43 tooth) same as stock, but when I am cruising at like 70-80 mph, my rpm's are between 7 and 8. Is that normal? I hate it because it cruises at such high rpm's. I feel like I need to constantly shift it. Is this common, and what can I do to fix it???

 

That sounds high - how many teeth on your front sprocket? I cruise at 75 mph (indicated) at just below 6000 rpm, but I know my speedo and odometer are a little high, based on comparing my odometer to the mile markers on the side of the highway.

When it's time for a new chain and sprockets, I'm going back to stock, since I spend a lot more time commuting to work on the highway than launching from stoplight to stoplight.

 

I also run at about 6k rpm at highway speeds with stock everything.