I am new to V6 Magna motors and have to ask, are there external differences between the TH 3.0 liter and 3.5 liter motors? Things I can look at and say "this is or is not a 3.5 liter motor". Reason for asking is I am told that a car I am interested in is being promoted as a 3.5 liter. I am not 100% sure and I am looking for advice re the differences I can pick just by looking.

Engine number is a clue. 6G72 is 3L and 6g74 is the 3.5L

As mentioned the engine number, which should be in the cars registration papers (or on the block itself)

Engine number, alternator bracket looks different, they are the 2 main give aways, alt bracket you need to know what both look like to tell them apart

Thank you gentlemen, and ladies.