Stereo & Electronics - Anyone running 12" Kicker L7's in a subthump?

Im debating if I will need to add polyfill to my box as its only 1.2cu/ft and sealed. Im running 2 kicker L7's and im wondering if anyone has used polyfill in the box to help. I think they could have made the box a bit bigger in the inside going into the trunk a little more but all well

what amp is one them both?

Im running a Hifonics Brutus BX1500D that ive been using for the last 5yrs in my cars... The specs for the sub calls for 1.5cu/ft minimum space and 6.0cu/ft max... which is why I hope to gain more with the polyfill

I have two 10 l7s each one of them is gettting like .89 ft3 ( behind the seat in a single cab yota) Sound pretty good it isnt gonna give you the shaking bass but that wasnt our goal.
I also have 2 15 l7's in a 11+ ft3 box tuned to 34hz and they sound amazing all around