340/drivetrain build advice

Thanks for all of the advice guys, I'm seeing several possibilities. There is one thing that we didn't talk about and that is the altitude where this car lives. I am in the Denver area and if I'm not mistaken that should have some consequences on how this should be built.

What do you guys think?

I also started another thread on the possibility of considering the 1.88 intake 308 heads for that same reason.