that be great if u can help

 

so that guy messed up with the specs lol i noticed it didnt make sense

the box should be 13 tall, and port is 11 1/2 tall, not 10 1/2. but i dont know how much that will change the tuning

 

I'm not going to say someone messed up with thier specs, this person may have some godlike understanding of the forces of sound waves or something. I'm just telling you what some simple software numbers are.

this is for an early 90's cavalier? (guessing from your sig)
if I remember there's a fairly large rear deck that we can run the port mouth through to keep vent activity high. what is the hight from the bottom of the trunk to the top of that rear deck?