Re: pro street tires
Given who the OP is, I think it is safe to eliminate pinion angle, driveshaft balance and tire balance.
That only leaves three things:
1. Belt separation.
2. Wheel run out.
3. Tire run out.
Freddie, if you were close to me I would be glad to loan you some big rear tires & wheels to try out.
Personally, I would suspect the tires first. But, to be sure, you best check wheels for "TRUE" before going much farther, although you did say you needed tires anyway. Perfect time to check wheel run out if you are on good terms with the installer. Put the wheel on the balancer sans tire and check with a dial indicator. Virtually EVERY wheel manufacturer specifies 1/16 runout as acceptable. I call BS, especially if you are going 110 mph or better. Less than 1/32 in my book.
There are guys out that that can true up wheels and get them right on the money.
One other thought: what wheels are you running? If they are aluminum of any kind and the manufacturer claimed they were "lug centric" that is also total bs. I run Centerlines on two vehicles. One set of wheels manufactured in the 2000's, and one from 1972. I love Centerline wheels, but the claim that they are "lug centric" is crap.
I had hub centric rings made for both. How can a wheel that has an acceptable "range" of clearance for shank type lug nuts be "lug centric"? They can't. It is a sham propigated by wheel manufacturers to save money by producing wheels with a giant hub center that they can then drill for different lug patterns. JMHO (but I am right on this one).