this may help you, it's as close to the dimensions you provided that i could get, hope this helps some. you can adjust the frequency to fit your needs, but keep in mind that this is the smallest recommended enclosure for those subs. [1.75 cubes each]
I know for sure his box was 3.5@ 34Hz and it got loud and he was quite happy with it. SQ wasn't the greatest, but I don't think CVR's are known for sounding good anyway...