you're probably going to spend $7-8k on a new rig, which would be more than a complete rebuild (there's a thread on mud listing pricing) if you do it yourself. i have a spare engine that someday i may build. i'm expecting 4k.
if you plan on having an 80 long term and your rig is where you want to be and has a good frame/body, i'd
a) get a daily driver and when you have the money, complete rebuild on the motor
b) quicky head job and start stashing money for the rebuild.
if you don't see yourself in your 80, then buy another vehicle. keep in mind that you know what your rig needs, you won't know what another used rig needs. you may buy a $7k rig now and have to drop a grand when something goes wrong.
i don't have intentions of my 80 being my daily driver forever, the body and frame are rusted crap, but i plan on another 80 of the same vintage, so anything i do it can be transferred to my next rig.
ige tlca #1431