2008 6.7lt to 4l80e.Did not fit without modification to engine block and the new 6.4 starter. Bolts were recommended and sold as well but were not needed. They are the same as the original on my engine. The bolt holes in the adapter are larger in diameter then necessary. Clamping load capacity is worrisome. Fit could be better. For the price of this kit I expected much better results. Disappointed in fitment and add on hardware recommendations. For this kit being specific to my needs I wouldn't expect so much modification.