h3xperiment

Great suggestions! Thanks everyone for your input. Can't wait to get started on this. @509_521: Wanna trade?

Nice! If I go that route I will definitely get this (or similar). I'm starting to think I might just install bucket seats because that bench seat does not hold me in obviously, and I want to feel more secure when traversing those bumpy-ass mountain roads. With the bucket seats Im sure I can fit at least a small proper sub between and mount the amp under a seat and speakers in the doors or something.

Fixed the link. I thought I checked that before posting. @kingrat I have thought about that, but I have reservations in doing that since the bed is not connected to the cab. Although thats probably not as big a deal as I think it is. Also, i plan on purchasing/making a canopy for the bed so I can go camping in it so that would help with the weather a bit. I will keep this option in mind. @hobospyder, Rjawm I've never heard of those, will give this a further look for sure! Looks like I could install 2 small ones, although they are a bit pricey. Thank you all for the help, and further suggestions and tips are always welcome! :D

The truck is a 1975 620 SC longbed. Absolutely no room inside for a fatass sub as Im sure some of you know. the only thing I can think of is shoving an active enclosure slim subwoofer like THIS under the bench seat. my concern with this is bass quality as I listen to a lot of super bass heavy electronic music as well as gangsta rap (my translucent-white, southern Oregonian ass) I dont want to rattle the cars around me but id like to get a very heavy butt massage from it. I'm sorta stumped other than this option. Thanks for any help! :D