4x4 Driveline Angles

[Rat72]

I'm putting in an LS2 and 6L90 into my 72 4x4 and am having a heck of a time figuring out the positioning of the engine. I've read a ton of posts on driveline angles and a lot of them say about 2 degrees rear tilt on the engine is good but nobody explains why? After thinking about it the engine will probably run fine at any angle so I'm guessing that it comes down to driveshaft angles. I built a spreadsheet to determine front and rear angles based on engine tilt and both front and rear driveshaft angles improve as I tilt the engine back. I was surprised because the engine tilt adds directly to the driveshaft angle but the lowering of the transfer case (and driveshaft) is more significant. But only by a little. So why shouldn't I set my engine back at 6 degrees? It helps the front and rear shaft angles. The rear angle is negligable and the front angle is 24 degrees and 31 degrees at full droop. The CV joints I use are good to 32 degress. Anyone have some thoughts on this?

Thanks,
Whit