3 1/2" chamber questions

[marlin1895gs]

hey, im lookin for a good all around shotgun, something that will most likely come with the long barrel, etc. as a hunting shot gun, it needs to have adjustable chokes, and a 3.5" chamber, it'd be cool if i coudl in the future put a pistol grip and shorter barrel on it, with a side saddle etc. run them big slugs. can i do this with the 870? i dont so much care if it is pump or semi auto. able to hold 8 shells would be nice, but only 6 will do. (2 3/4" of course)

 

[Fox]

The 870 is the same for 3" or 3 1/2" with the exception of the receiver, furniture should be the same and the barrel lug should also be the same so fitting a barrel meant for a 3" gun should be no problem, just remember that the new barrel cannot take 3 1/2" shells.