If you still have a stock floor in the truck you can get to everything from the top if you take the floor panel out around the transmission, it's big enough to pull the transmission completely out through. If you have the SM420 granny box you won't be able to see anything move from the outside, all the linkage is contained within the transmission. You can pull the whole top cover off or the side cover and check out the shift forks and stuff, it's pretty easy. Put the tranny in neutral before you try to re-assemble it. Felpro has new gaskets.
