So how strong are the guys? I would guess around 6 to 7 hundred pounds. With 4 of you, you will know that you are all lifting. Fortunate you just have a short distance to go. Last car I helped with was a 66 GTX and I think there was six of us and it was quite comfortable.
Is it a convetible or a coupe? The subject line says convertible, but the text says coupe. If convertible, I'd presume you've got some steel bracing the door opening.