I'm replacing an interior door -- including the original jamb -- in my house with a new 30" pre-hung door. With the jambs, the new door is 31 3/8" wide. However, the original rough opening is between 32 1/2" and 32 3/4" wide, leaving me a big gap between the old frame and new jambs. The hinge-side stud is straight and plumb, so I'll probably not have to shim that side by much (if at all), which will leave the bulk of the gap on the latch side.
Can I fill a gap that big with shims, or should I think about nailing a 1x4 to the latch-side stud first? If I use shims, I think I would need several to make up the right thickness: is there a trick to holding them in place while I secure the door jamb to them?