1967 mustang mod question

I have a 1967 gt coupe, I wanted to make a 1968 428 CJ Coupe, I like the 67's a lot and I am just wondering if I should change it to a 68 for the sake of looks. The car right now needs a ton of work, 2 years or so to piece it together but the car is kind of bare with no engine or trans, no fenders, valance, grill, hood, etc. Like I said needs a lot of work. But my question is still to convert to 68 model, I know there is not a big difference in looks except the rear quarter vents. I do and don't like them. What would you suggest?

P.S. Looking for a full restoration, toy car with power, Engine of choice 390 cid, the 351 looks nice but wont a big block and can't afford a cleveland. Also have restored my 65 coupe, 66 HiPo 289 coupe, and Brothers '71 BOSS 351C.

Well about the engine...

I like the 351 and 390 better then the 428, I don't have the money for the 428. Would rather have a 427 cid but that is a different story. I really just like the styling of the 68 428cj. I like both of the years but I just didn't know whether or not to leave the side vents alone or to remove them to add to the styling. I am just trying to get feedback. I really hate changing the year and messing with the origional factor but I really don't plane on selling it ever and or really taking it to shows.