For my two cents again, read my above post. But if you're in doubt I have a solution for you. Mock it up with some flat wood blocks and check your pinion angle. If it's good get flat blocks, If you need correction one way or the other get the tapered and run them in which ever direction you need to.
Also here's a quote from ORD
"Pinion angle is a popular question with this kit. The quick and easy answer is that there is no quick and easy answer. Proper pinion angle depends on drivetrain length, wheelbase, gears, tires, vehicle speed and more. It usually boils down to what works for your truck. In general, the shackle flip sets the pinion angle about right for most 4" to 6" lift Blazers and shortbeds, especially the later models with the aluminum transfer cases. Longbeds and Suburbans will probably (but not always) need to shim the pinion down a few degrees for minimum vibration"