What do you mean by standard bed? To me a standard bed in an HD truck is 8' and a short bed is 6.5', but the half ton market has skewed those definitions to the point they don't mean much.
I have a short bed crew cab Ram with a rail mount Andersen I run flipped to the rear. My experience as it relates to your questions:
- I do not have bed rail clearance issues.
- I cannot make a 90% turn but I can turn at full lock going forward either way without making contact. The circumstances that a person would need to turn a fifth wheel 90% would be very limited (I'm being generous here).
- My fifth wheel does not ride nose high.
- No blocks necessary.