I did the V code front springs last year along with some straight 4 inch F350 blocks I had laying around. I had a vibration when accelerating so I installed some 2 degree tapered wedges that are used for setting the front caster on the bigger trucks, vibration is gone.
Last week I replaced the stock rear springs with B codes and used the stock Excursion 2 inch rear blocks. The rear was a little low for my liking, I was used to the way it looked with the 4 inch blocks and stock springs.
I installed the tapered 4 inch F350 blocks and it sits a little higher in the rear from before, 1/2 inch, but looks a lot better and the ride is not affected. The tapered blocks eliminated using the tapered shims that I used to prevent the vibration concerns I was having.
I had to trim a little off the right rear lower leaf on the B code to clear the exhaust pipe, It was hitting when the X was raised on the lift at work.
It sits about 1/2 inch higher in the rear from what it was with the stock springs and 4 inch blocks. There are some Pics in my signature of how it was before, I haven't taken any pics of the X with the B codes or 05 head lights yet.
over all it rides and handles a lot better, I have to see how it does when towing the travel trailer, maybe this weekend if not defiantly next weekend as I am going on vacation then.
The Rancho RS9000X shocks work fine with this setup but both the front and rear shocks top out when raised on a lift. On the road they are perfect. I am running both the front and rear on the #4 setting unloaded and the #7 setting when towing.
FMT