I got a shop to install two 6x9's under the dash, they built some custom boxes and mounted them in there so you can't see them and they are not taking any leg room, I also have a amp under the seat. I'll post pics and a review when I get the truck in about 3 weeks on this thread
http://67-72chevytrucks.com/vboard/s...d.php?t=308093
good luck!