goodbye 5.9, HELLO 6.7!

http://inlinediesel.com/forum/topic.asp?TOPIC_ID=1027

a manager on a district level called me about my recent experience at 
lithia, apologized for the assinine treatment i had received earlier, and 
asked me for another opportunity to earn my business.  i heard him out and

in the end i got a deal i couldnt refuse.  so far im VERY impressed!  the 
power, the 6 speed automatic transmission, and the exhaust brake are just 
awesome.  i do have questions:

1- i have been warned about putting really heavy bumpers on my 5.9
equipped 
cummins due to wearing out the front end prematurely.  is this still an 
issue with the '08 models with the 6.7?  im hoping youll tell me the front

end is built up to handle more weight.

2- the particulate filter sounds like ill never get any black smoke again.

what can be done if anything to get around this system?

3- my wife needs tires on her '04.5 so im going to put the tires on my '08

on her truck and buy new tires for my '08.  i want a somewhat aggressive 
(along the lines of a bfg MT or trxus mud terrain) E rated tire that will 
last at least 30,000 miles and stand up to heavy towing.  id like to be 
close to stock, perhaps just a little taller, any recommendations?

4- salesman says my truck has a limited slip rear but i find NOTHING to 
substantiate that in paperwork and there is no tag on the differential 
cover.  any ideas on how to confirm this?
thanks,

Nathan In Montana
http://ConcealedCarryForum.com