Lookin for a shallow 10in replacement

I have Polk MM1040's right now and i dont like how close they are to the backseat of the double cab. My question for yall audio gurus is.... what sub do i go for? Seeing as there isnt a whole lot of area in the box the guy at the local audio store said a Rockford fosgate 10in P3 Shallow mount would perform very well with the limited box room. I know my polks would hit a hell of alot harder if i had the right box for them. So im just trying to find out if there is a sub that would do well with that box.... so im open to suggestions.

Also 2 Polk MM1040 10's for sale Pretty much brand new.

 

Saturday my install should be complete on my new system and I'll hear my Rockford P3SD4-12 ... My installer said it hit hard in the shop but I'll keep you posted after I hear it.

 

Thanks man, yesterday i ended up cutting the box to fit two JL 12W 1v2's... they arent shallow subs but where the sub mounts is actually higher than the surround itself on the sub (which is what i needed) I havent really rocked on them yet to let them break in a little but just my everyday listening they have alot more bass than the 10's and im still using the same amp. Still let me know how it sounds man.

 

Will do Woody.