I have a 2008 4x4 double cab . I didn't care for jumping in my truck every time so I had a tundra racing 1/3.5 lowering kit installed . After driving the truck home the front end felt a little different,hard to explain but felt sort of nervous , like it jumped around. About a week later I had new 26" wheels and 305/30 tires installed , now I have a bad shake in the front end at speeds above 45 and real bad anything above 60. I bring the truck back to the tire shop and they spun the tires 180 degrees on the rim and road force balanced my tires a second time . They assured me my rims and tires are balanced . The shake improved a little but I still don't like how it feels above 60 ...I know I need a wheel alignment after the 1" front drop but I was told it wouldn't help with the shaking ? Could it be my shocks ? I think the tundra racing kit uses some sort of sleeve on the spring ? I'm at a loss and before I spend $$$ replacing unneeded parts I figured I'd ask if anyone could help me out.

Your truck needs an alignment, and it needs it badly.

You have described the classic symptoms of steering instability (shaking at speed that gets worse as speed increases) and the classic cause of that instability (changing the geometry of your front suspension without aligning it afterwards). In particular, your truck has insufficient caster to provide steering stability.

The rule is quite simple: If you change anything on the vehicle which can change the wheel alignment, then you need to get the alignment set properly after making the change. Installing a lowering kit is one such change.

A bit of background might help. I see this is your first post in this forum, so likely you haven't read much on this subject here. You'll find the following post worth reading:
http://www.tundrasolutions.com/forums/knowledgebase-archive/2541-djs-alignment-setting-recommendations/
Now, please understand something carefully. I have made recommendations for over a decade concerning the proper alignment of a Tundra. The specific alignment settings which I recommended in the link above apply ONLY to the early years of the first generation Tundra. Yours is a second generation Tundra.

I suggest you have yours aligned, and make certain the alignment shop gets it right. Have them set camber, caster, and toe DEAD ON Toyota's recommended settings for YOUR vehicle. Don't accept the statement that "it's in spec" or "it's in tolerance" or "it's good enough". Make sure you get a "before" and "after" printout, with the correct alignment specs shown.

Most importantly, do it before it kills you. Steering instability is dangerous.