Probably a little late to help you... this is my slapped together exhaust (first time building an exhaust like this where I had to bend and weld tubes) - but here's mine for now. Cheap 28" long glasspacks for the time being. Probably slightly leaky.
https://youtu.be/kUoSWj7fvXo
https://www.youtube.com/watch?v=nWyB34SdS9U
Exiting under the cab... unbearable inside
https://www.youtube.com/watch?v=KIYlBSADm3A