Not 100 percent sure on a Toyota, but on GM, the last 5 or 6 numbers ( or so) of the VIN # match the same amount of casting numbers on the engine block. Again, its the last set of numbers on the block. Im sure Toyota is simular.
There is an federal anti theft standard 49 CFR Parts 541, 542, 543 which requires the vin be on all the major parts. Those tags on fenders hoods etc are everywhere to discourage chop shops. I went to the local toyota dealer but as usual they are useless
Engine Model = 2TR-FE
Model = Tacoma
Model Year = 2005 – 2009
Serial Number = 2TR- 1 ######
1: Plant Code (1 – 9)
######: 6-Digit Serial Number (0 – 9)
Location: On Left Side of Engine Block, towards Rear of Block (as shown below)
If it is a major sales outlet they will not risk losing their customer base for selling "not as advertised" parts. Buying through a dealer he risks his dealership franchise. Not sure where your buying but I am always more concerned with the internal condition (did the original owner change the oil etc.) Just my 2 cents. Have the sales outlet give you the info you request that should put them on notice your not a novice.