box size

So I've had alot of help 2 to 3 people and all there information is great I just want to hear other people's advice that's all. So the box I need is 4 cubic feet net so there's a box that's 3.5 cubic feet net instead of 4 that would be a better fit in my car would that make a huge difference...

im looking to run 4 american bass vfl8d4's in a 1997 single cab chevrolet s10, but my one and only problem is i cant find any box size specs anywhere for these woofers... i would like to complete my transaction on ebay for all four, but, if all four arent going to fit in my truck why get four...