There have been a lot of posts lately regarding the fitting of sidekick parts to other handi rifles and shotguns. Unless it is the buttstock, trigger guard, or sights, the answer to most of these questions is likely no.
Take a look at the pictures below. You will see that a sidekick frame is almost an inch shorter than a SB2 frame. There is no practical way barrels can be made to fit each other. The underlug of a sidekick is much shorter and about an eighth inch narrower than that of the other barrels. However, the length of the forend mount to the breech is the same. This leads to a difference in forends. The sidekick forend is about an inch longer from hinge to screw. If you are dealing with a wood forend, you may be able to drill different holes and countersink them. With the hollow synthetic stock, this won't be possible, as the plastic thickness is only built up around the original screw location. It is very thin in the area you would need to drill to fit a sidekick forend to a rifle frame or vise versa.
