i have a dpms lo pro classic upper with the 16" bull barrel. i would like to install a set of yhm freefloat handguards on it. my question is.... i want to install a longer set of handguards on it so the barrel is more covered. the gas block ( small/square with pit rail) has 2 set screws and is easily removed....can i just buy the rifle length handguards and just install a rifle lenght gas tube? or is it a lot more work? thanks in advance