@deanfj40 the reality is that if you don't now have any smog equipment, you are likely screwed. There is no new smog equipment available, so everything you use will be old, worn out, and probably not even working. And it's crazy money. Your budget will be spent on nothing but smog gear, and then you'd still need a running motor.
I went the other way. Bought a 71 frame and title, and swapped the entire truck onto the new frame. Then desmogged the motor since legally the truck is a '71. It was several weekends worth of work, but not as bad as I thought, and I've had 10 years respite from the smog guys. And a desmogged 2F runs surprisingly well.
Because even when it's all done and can pass smog, it has to pass again every 2 years. And 78 smog gear was poor to begin with and hasn't improved the last 40 years.
I think you're going to need to re-evaluate your budget. Nothing wrong with a good running 2F, but getting it to pass smog is a nightmare.
Motor wise, I'd look for a used but running 2F out of an FJ60. Usually a bunch around for $500 or so. Make sure you can see/hear it run before you buy and hopefully get at least a compression test. Any newly installed 2F is going to deserve a carb rebuild, so that's $350 right there. By the time you add belts, waterpumps, thermostats, gaskets, and exhaust etc, you're close to your stated budget, especially if paying someone to do the work. Don't forget you need a bellhousing, flywheel, clutch etc. Hopefully you have some of that. It all adds up fast.
And to do a V8 swap you are looking at WAY more than your budget, just be aware. Doesn't sound like you'll do this yourself, and a clean swap and install could easily be $10,000++
Any relatives in nearby states where you could register your truck? Not that this is legal, but it might be your best recourse.