I have a 1968 350 coupe that had the original 2 speed auto trans switched for a 3 speed auto transmission before I bought it. Since I know it won't take away from the value I'm thinking of switching out the auto transmission for a 4 speed manual. I have a shop that told me they can do it for $3000.00. Two questions....is that price about right? and What should I tell the to put in as far as a fast with low end power transmission?