S10 Blazer, Box for 2 15's

can i put the ports towards the bottom facing tailgate? i thought i read somewhere porting on bottom or sides with round ports wasn't good, just askin cuz i'm tryin to leave some flat box space right behind seat to mount a box for 4 6x9's ontop of it....yea I read alot of good reviews on the new sxx and seen some nice videos...I did hear people talking bad about re now to...I tried finding other pairs of 15's for 500 or less shipped but failed so I got these shipped brand new for 500...right now I have 2 12 pioneer pro series and I'm feeding them 1000 watts each and believe it or not they hit hard and sound decent doing it, ppl can't believe they are pioneers when I tell them

anyone know if it's ok to put 2 round 5" ports facing towards tailgate and subs facing up...or would I have to do a slot port to do it that way? I thought i read somewhere you can't use round ports in certain place on box....trying to use round ports to gain a little room..thanks

do you think 2 5" flared end ports ports would be ok without being to noisey?

I want it to get low get loud and sound good and yes my daily driver.. What should i tune it to?