Man, thats weird because I know Big Daddy Dwayne Gutridge personally and he never had a Super Snake, only 2 07 GT500's a grey one and an orange convertible. Also I know for a fact that he builds his own engines so, maybe we are talking about a different guy. I know a few shops that use him for tuning and engines as well. All seem to have nothing negative to say other than maybe he's a little expensive but the work was great.
I know the guys over at Downs Ford have nothing but positive things to say about Big Daddy. To the OP have you called anyone yet?