I hated their instructions, actually just the pictures. Instructions were good but the pictures looked like theyd been photocopied about 100 times over. Still got it done, and runs wonderfully.
Its pretty simple, the hardest part for me was reading the bluing on the ring gear teeth, didnt show up real well on the black of the tooth. Id suggest finding white lead or something similar rather then the bluing.
Go for it, its just money!
Jeff