What rear end gears for 904?

So far I'm hearing 3.91 and 4.10, but I'm not sure that I'll be happy buzzing down the interstate at 70mph with 3.91s or 4.10s.
You kindof gave cruising up, when the 400hp cam went in. I bought an overdrive to solve that. You may get away with a trailer; mine is/was a DD