So when does a tiger stop being a tiger when parts are chopped out and either fabricated or salvaged from an Alpine , it also seams that the 260 engine is replaced with a 289 or larger rather than restoring the 260 in a lot of cases ?
A very quick TAC summary.
TAC doesn't declare a car a Tiger or not ... It is a process that identifies the unique modifications and process that Jensen used to produce a Tiger and some of the unique aspects of the Tiger shell from pressed steel vs and Alpine.
There are signs of this on the cars front to back.. drive line, trim etc have nothing to do with TAC... It just looks to identify the lineage of the body
You could replace all the outer panels of a car with some from a donor and you can still identify the tiger sheel... I know you could add a complete from clip firewall foward to a car and it would still pass TAC if the rest of the identifiers are there from the firewall back.