a friend of mine is building a b16 to turbo and was wondering if he would have to upgrade his crankshaft and if so which one should he go with

 

As long as its not all scarred up its good. Possibly get it micropolished and balanced. Other than that, stock cranks seem to have a lower failure rate than aftermarket. If you do need a new crank, get another used stock one.

 

depends on how much hp hes looking for i believe b series cranks are good for 500hp

 

They're good for a lot more than 500hp