The problem with the "Tanker" Garands, is the quality varied WILDLY, depending on who built it.
Those built by reputable gunsmiths like Orion or Fulton work great.
The problem is, most of them were built by fly-by-night fast buck artists.
There is no way to determine if one is Ok or not, except shooting it, AND having a qualified M1 'smith check it over.
In any event, buying a Tanker of unknown quality is strictly a crap shoot.
You may get a good shooter, you may get one that simply won't work properly, or you may get one that's actually dangerous.
If it's made up with a commercial cast receiver, the chances of a bad one go up considerably.