Aluminum or steel driveshaft ?

[Too Many Projects]

This is just a street car with around 600hp at the motor, no need for exotic parts. Just don't want to break anything again, when I do go play.
Freddie, looks like plenty of room for the 3.5, but I'm not going any bigger. I'd like to stay at 3", but nobody wants to build a shaft 58" for 6,500 rpm. Maybe I should fib and tell them it's for 5,500.
I had a long talk with my rear axle guy about all this last night. I told him all the options I was getting but that I thought I would just stay with the c clip and stronger axles and he agrees. He mentioned the eliminators leaking too and I don't need a new issue from "fixing" another one.
He had a 3" driveshaft made locally for his Camaro but doesn't know how high an rpm it was balanced for. I guess I could call them and see what they say.