Me and 2 other buddies are making a box blind. We have all the lumber to make it. My question is, we planned on making it 8 feet by 8 feet by 8 feet tall with the roof slanted to 7 feet in the back. Does that seem way to big?? I thought is was about right but idk. Any info or suggestions would be helpful.

i say better too big than too small!

I wouldn't make it any bigger than a good ground blind. Go and sit in some and you'll have a good idea.

That's too big for my program. I've built threemyself, all were around 4' x 4' x 6' tall.