I have a Z1 in my 2500HD, and I will be adding a computer to the truck. I am planning on hooking it up to the A/V input, but I realize that the resolution would be really big at 480 by whatever. Is there any way to send video out to the A/V input at a larger resolution like 1024 x 768 or so?

It's possible. THe computer will need to have a video output. If it doesn't then you'll need a scan convertor to change the vga output of the computer to a regular composite input that the z1 can handle. As far as resoultions go, composite video has a set resolution which esacpes me at the moment. THe computer or scan convertor will adjust the monitor out put to match what the z1 needs as far as a video signal.