if i buy a box off of ebay that they say will fit in my truck will it fit becuse under my seat about 8 inches back from the front of the seat it has a hump in the floor annd the back seat angles down should i buy it then go from there or should i stay away from it and build my own
You could always raise your back seat up 3" using aliminum C channel like I did and then build 2 seperate boxes and then use one common front face. I know the back of the box looks fugly, but onec the seat was down, you couldnt tell and You have a place to hide the amps. In my case it was 2 800a2's and a older u.s amp. I built the front plate first to contour the floor and then did the 2 boxes. I would wedge the front plate between the bottom of the seat and the floor and then use a tape measure thru the side openings to mock up some measurements. Worked out ok for me. Wish I could remember the measurements as this was 5 years ago.
hope this helps. Plus, I had to liquid nail some 1/2'' x 1'' c channel between the two boxes to keep them from twisting as I took them in or out. I could pick that box up by my self and it would not flex.
Your best bet is to go with shallow mount subs. Shallow mounts offer the best possible application for pickup vehicles. Because of price I would reccomend going with a single shallow mount sub, because it will out perform any standard size subs that you can find to fit that type of application. That is if your not planing on removing your rear seat. Personally I like the new Alpine SWR-T10 Type R subs. You can get a pre fab box that is specific to your vehicle from Atrend. They offer a single sub enclosure and dual sub enclosure both available in a 10 or 12" application. These enclosure are specific to your vehicle make and model. You can check out specs on the Alpine SWR-T10 10" 4-Ohm component Subwoofer (SWRT10) and check these Atrend boxes from atrendusa.com for your truck their sick. These custom made to fit under the rear seat of GM EXT Cabs 88-98. The images here are the Line X coated boxes but they are also available in carpet.