DISCLAIMER:
These responses are based on my own personal experience and knowledge after years of working on Scouts.

1.   You can't put a CV Drive Shaft on a Scout II with a 727 transmission.  

2.   You can't put 35" tires on a Model 800.  

3.   You increase the compression ratio and performance when 304 heads are put on a 345 engine.  

4.   You get lower ratio gears for your TF727 by using motorhome tranny components.