Need advice on updated AR handguard

[trbii]

I’m unsure how to measure handguard lengths, does this look like a 8”? It’s an old, heavy, clunky quad rail on a LWRC M6A3 carbine. Thought I had to have a piston action AR 15-20 years ago, surprise, it’s a front heavy design. Was wondering if these new (to me), long, slender M-Lok slotted hand guards would lighten this front end? Somewhat noticeably?

 

[mouthpiece]

Looks more like 10" to me.
Some handguards will not fit piston uppers. Make sure it is either, compatible or, you'll be able to return it.