Welcome to the madness. A frame swap is a much larger effort than an engine swap. Whether it is worth it or not depends a lot on your long term plans.
You mention that you want to keep it and pass it on, but what is your use case for it? Hauling? Racing? Car shows? Commuter?
What other upgrades are you planning to do? Power brakes/steering? Disk brakes? Overdrive transmission?
I don't want to overwhelm you with questions, but having at least a hazy image of your final goal is needed to evaluate what the best initial steps are.
