Ok three questions for you. Any help with any of the question would be great.

1. I have an 8 inch notch. How much of the 8 inch's of the notch will I need to tuck 17's on my 87 Mazda?

2. I just cut out my bed for the notch. What do you guys do to strengthen back up your bed where the hole was cut out?

3. Where do you guys buy the trim that goes around the hole cut in the bed?

Thanks