Yeah Def drive one. In my opinion in your situation I would consider this:This is the EXACT problem I want to solve. I've got 4 little girls, a wife, gear, 2 RTTs, and a small trailer I'm hauling. Not to mention a front bumper, rear bumper, spare tire, etc...
You and @White Stripe are making total sense. You better stop. Are you saying I should drive an 80 with an LS before I dismiss it?
All these comments are swaying me in a direction I never thought I would go. Now I just have to find someone with an LS swaped 80 near Southern Utah that I can bribe into letting me drive.
What is your maximum realistic budget for your cruiser in this situation? Can you even swing a motor swap? Then your not looking at unreasonable options. Also consider since your cruiser is still drivable that buys you time to save up.
What are your local motor swap laws?
What driving experience will you and your family be happy with? Some options like a 6bt may be too loud and rattly for you.
How long are you going to keep your cruiser?
How will this affect the cruisers value? Some swaps may not increase value hardly at all. Others will make it worth much more.
What are your overall uses for the truck? More cubic inches gives more low end torque. In the gm v8 category alone you can go as small as 4.8L and as big as 8.1L.
Also consider elevation your driving at since higher elevations take away power with thinner air. A 4.8L may be ok at sea level, but will be slow up high.