Hello, Is there a way to get the rotation the aligning just perfect? I got a block that is
360w 348l 36h. and its on a slant like \
Is there a way to get to the rotation perfect instead of doing guess check and revise? here is a pic

http://www.snipa.com/Zer0/pic.JPG

I don't think so.
You have those little "arrows", which show the angle the texture is turned in 3d view. You can use those to give you a good idea on how good the texture is aligned.

like insta pointed out , theres no hotkey to get it to align

your arrows and the texture rotation tool is all you got :)

use trig to get the angle, then just use the "fit" button. ok you'll need to tweak it a tiny bit after but it works.