Need some help with enclosure once again... 2x12 DC LV3 M2 D1

[akrja_07]

I posted a while back about help with an enclosure for 2 type x 12's but switched subs before I could start building the box. I now have two DC level 3 m2 d1 12's going in an extended cab 01 Silverado. I am thinking the enclosure should be around 3 cubes tuned to factory specs or slightly lower. My ideal dimensions are 45 x 15 x 15 but can give or take a few inches from anywhere. From what I understand, subs will perform best is they face up and port faces the side, does that sound right? Also curious if I should do a double baffle and if I should do any bracing... Thanks in advance, once again.