I have read many threads here about upgrades to WH line. I have the 2006 Itasca Model 35U with 12000 miles. After all the reading...I have selectively added:
a. Taylor Extreme SP wires. Wow...very noticeable smooth and even engine acceleration. No more slight hestitations...as it went through gears. Easy to change out through fender well and dog house.
http://store.summitracing.com/partdetail.asp?autofilter...1%20115&autoview=sku
b. Centramatic Wheel Balance System. Installed first set (600 Series) on steer tires. MH rides and feels like it's on velvet.
http://www.centramatic.com/
c. Doghouse Insulation. Cut engine and tranny sound 30-40% along with summer engine heat and winter cold. Easy to self install.
http://store.summitracing.com/partdetail.asp?autofilter...319+115&autoview=sku
d. K & N Filter to stock intake. I've used K & N filters for past 7 years in my Ford trucks. I have also done the cleaning and reoil on them. Here lies the biggest issue..reoiling the filter so as not to gum up the intake MAP sensor. Just follow the K & N instructions and you won't over oil.
e. 100% Nitrogen (N) in all tires. I've used 100% N for 5 years in two trucks and one 35 foot FW....and virtually eliminated major tire heat failures...and frequent pressure service checks. Last trip I took in my Itasca...three weeks..3800 miles needed only one pound of N to each tire.