I am trying to install a garage door opener and I have to fasten 2 2x6 on the ceiling and the header wall over the door. I used stud finder to locate 2 studs on the header wall and tried to use 4 4” lag screws to fasten the first 2x6 on the header wall (2 screws on each stud). However, I found it very hard to put the screws completely settled in the studs although I already predrilled the pilot holes. Is that because the 14.4V power tool not powerful for this and I should use a wrench instead or is that the 4” lag screws over killing? Can you please recommend proper tools and fasteners?