Well, I threw an Alpha 12 V1 in my cousins Honda Civic trunk car on a RD 1000D to play with. The box is 2.5 cubes at 32hz. On the dash windows up it did a 143.3 bass race Stock electrical and 4 guage wire.
Yea Canaan, they are pretty good. Even with seats up they still get loud.
As for you thieves, being in a blazer you should be mid 40's I am sure. These subs are so efficient it isn't funny. Those numbers were before break in as well, my cousin said it sounds like it is getting louder with break in to the ear .