4spd High RPM in 3rd Gear?

I think that is/was the case, something so simple. I got under the car yesterday since it was nice out and put it into third. And took it from a stand still in third and it acted like it should. Then to fourth and it acted normal. Went from a stand still in first and shifted to third and it acted strange again. Appearantly I can't get into third by shifting. At least not most of the time, since It did act correct a couple times the previous drive with it. Sounds like I have some adjusting to do, but no real issues.

And it is clearly not the clutch, If I'm going 30 in 4th gear and floor it it will throw me back in the seat I'm sure. It is not short on get up and go. It is easily the most powerful feeling (power to weight ratio) car I've been behind, far ahead of the 389CI 71 Firebird I drove a few years back, and at the time I thought that was monster. Although there is a timing miss for a second before it kicks in.