is it normal for my engine to hang around 3000 RPMs at highway speeds?

i own a 1983 Z28 Camaro, 305 LG4 V-8 backed by a T-5 tranny.
i'm not sure what gears i have, but i know that could have something to do with it.

i'm just wondering because it seems weird to be sitting in the right-hand lane doing the speed limit with my engine revving around 3K... and yes, i am in 5th gear!

(when i say "highway speeds" i'm talking around 65-70MPH... i am not exactly sure how fast i'm going because my speedo isn't working right now, so give or take 5MPH - however, i don't believe i'm going any faster than 70, so maybe it's more like 65)

 

Sounds like 4.10 gears or somthing. My car with 3.73's does 75 mph at 2750 rpm.

 

75MPH would def. put me over 3000RPMs!

it just doesn't seem right, i feel like i'm putting to much stress on the engine by sitting there crusin' at a nice constant speed with my engine revving so high.

where's 6th gear?!? haha, that's what i need, an extra gear!

i guess i should just stick to city driving with that car