1st post in 16 years!

It's been 16 years since my last log in so go easy on me. I'm looking for a suggestion for a sub?

What 10" sub will fit a .9 sealed enclosure with a mounting depth of 4.75 inches? It will be on an old Punch 500 (500 rms x1 @ 4 ohm or 250 rms x2 @ 2ohm). I have two enclosures.

I don't know anything about tuning I just want what I have to sound as best as it can. It's in an old antique truck, not trying to win any comps here or break the bank... Any suggestions for a sub?