Well... some things are subjective, others are not as is the case of performance, if you care about performance, you can use a car performance simulator to virtually take this (or any) cars for a ride and compare
it depends the 1965 because its a little older and its the first year the mustang was sold (not including the 64.5). but the 390 is more powerful. but thats not why you buy a classic mustang. they are not very fast they just look sporty. if you are going for looks, speed, and a classic buy a 1969 mustang fastback. any kind in my mind fastbacks are so much nicer looking. but in the end its what you are going to use the car for. so if its shows get the 65 but if you just want to drive 68
Ask any true stang owner having a 65 gt350 is like owning a picasso its beautiful to look at,.rare and gain extreme value, and you will probly never have one .... Its an american ICON. The 390 is a beauty too however the 350 is whel. Amazing
The 65 GT 350 is a Shelby that comes with a 289 and much more desirable than a 68 Mustang GT with the 390 engine..the 68 Shelby GT500 had a 428 engine is is highly sought after, but not as rare as the GT350..