The NA engine cant not handle the abuse of the turbo (pistons, cyclinder wall, head, valve, etc.) I mean you can turbo an NA but you will blow something if you go over 7psi. as for visual inspection, what I would do is get my self a turbo engine and do all of the following and when it come to smog check, just take out ur turbo and put in the na, and visa versa and you wont have to worry for another two years. Just my two cents. which part of sac are you from, Im pretty close by