Hi. Welcome to the forum! There is a 67 Lemans on Ebay in my neck of the woods for $1450. He has a GTO taillight section for it. I guess he wanted to clone it. I think it still has the 326 but not sure. It would be great to either restore or customize it.
The 66 and 67 body styles were the same but the trim and taillights were different. Correct me if I'm wrong guys...but I believe the front bumpers are the same on the lemans and gto but the rear bumpers are different. If going for a 65, that would be a totally different body style. Like 05GTO said, the GTO didn't become it's own model series until 66.
If anyone is interested, 05GTO posted a new thread in the southwest region for a GTO fantasy getaway to Vegas in October.