Hi Guys - I own an DPMS 308 Carbine AP4 ( I think it's a gen 1 ) with the aluminum round free float barrel - I want to ditch the free float setup and go original - I bought the delta ring kit and barrel nut but I'm having a hard time finding the standard two piece molded ( I think they're referred to as clamshell ) handguard - Will any of the old pair of 223/556 carbine two piece " clamshell " handguards I have work - Both the 308 and 223/556 have sixteen inch barrel lengths Thanks in advance for any help