I have a 2006 Silverado with a beast of a 4.8l and well the 4l60e took a crap so I bought a 2008 LY6 6.0l and the 4l80e , I bought the Circle D 278mm HP LS 4l80e 3000-3200 converter and both TCI Flexplates 399753 and 399754 , the 399754 doesn't bolt up to the converter, the 399753 bolts up but it bottoms out on the pilot bushing not letting the trans go all the way in , any help would be greatly appreciated