my yard goes flat down flat down. the first down is about 20 or so feet long give or take. the flat after that is only ten. in the winter i make a kicker on the flat and use the down for the landing. i usually get alot of air out of it which is nice. i use two factor x jumps the ones that are black and plastic then build over and make that jump huge. i forgot to try them alone because i will be using them for my jibs this summer. the box i am not worried about because it will be low. the rail i am worried about. will i get enough air to get up on to it? will the lip send me straight up? ive seen people use these im just afraid it wont work.
Dimensions: W 24 in; L 40 in; H 12 in

the rail and box are the exact same as those in the popular thread how to make a box and rail im just to lazy to get pics from it.