Is it possible to set up this machine as a AC DC Tig unit? Found one for a good price... I've heard people say a lot of good things about these old tombstones

While possible, I don't think it'd be as "fun" as a real tig welder.

You'd need a high frequency box add-on if you want HF start, otherwise you're doing scratch start.

No remote amperage control, so it's all on - all off. No pedal or finger control of current.

If you're willing to live with those concessions, then yes, it'd work. It'd probably be a better DC tig welder than AC welder (assuming it has DC already, and is not an AC-only unit).

Till you get down buying all the parts you need to do this even if you get them real cheap.

you would be a head looking for a econo tig or the smaller of the Syncrowaves like the 180 or 200.

i have a newer Thunder Bolt that was hit by a fork lift with the parts needed and labor it was cheaper to just buy a new unit. So the unit was scraped and I was able to cobble it back to workable condition.

So i had thought about doing what you are thinking of having a on the cheap Tig welder.

The numbers just didn`t work out.