I'm wanting to frame some inteior 3.5" and 5.5" wood stud walls. I don't have a nail gun so I was thinking of using screws. (I have built walls with nailers before).
My question is when using screws is it required to pre-drill the holes before inserting the screws so the wood doesn't split or can I just drill in the screws?
When using screws can I just replace the required number of nails with screws or can I use less screws?
What screws size/lenght should I buy for framing 3.5" and 5.5" stud framing and is there anything special I will need compared to basic nailing?
Screws will work fine, and there's no need to pre-drill. The code technically doesn't allow screws however. They don't have the same shear strength as nails do. The minimum code requirement is two 3-1/2" (16d) toenails. Toenails are required because end-grain nailing (or screwing) into the stud has very little strength.
If your wall isn't an exterior wall and isn't load bearing, I'd say use screws.