I wish you were down here near San Diego,
You have lots of fantastic resources down there around you that would be far better at helping you come up with a realistic plan than I.
I posted a link to Giant Motorsports down there in Garden Grove and they offer several “bolt-on” kits for full size rigs like the Bronco and Ranger and one of those might be easily adapted to the pig.
giantmotorsports.com
It wouldn’t surprise me to hear a middle of the pack setup would have 25K under the frame rails in housings, shocks, springs and fab work and if you don’t have what it takes to do the work yourself I would be prepared to hear a number similar to that.
The rules say you can run a pre-83 engine from same make, you would be wise to look into some of your Toyota pre-83 fuel injected options if you decide to pull the trigger on running gear that has a chance to finish the race.
IMHO the Pig is not your best option for a starting platform unless you have a burning desire to just be different and an unlimited budget to accomplish your goal. For example, the sister car to mine (The Angry Pig) finished the 100th running of the 1000 I believe third in class, they all had a great time and lived to tell the story. I’d sell you that car for 60k with all the spare parts and you’d need to spend a weekend on race-prep and head down run your own race and have fun without destroying your back.
If I were to build a pig that I thought had a good chance of finishing the race I would expect to be over 100k and know for a fact it would take my back months to recover, I believe this is why you don’t see a bunch of guys building rigs specifically for that vintage class, way better bang for the buck in other classes.
You might find something interesting in here.
The Baja 1000 is a grueling, dusty, treacherous race of endurance, and these are the only 10 cars capable of mastering it stock!
www.hotcars.com
Good luck and please keep us posted with your progress.