How Far Back Does Your Seat Go?

My 66 Barracuda seats are all the way back and I’m 6ft tall. It’s tight but when my oldest gets in at 6’3” he’s cramped. My youngest sits in the back at 250Lbs and 6’ and he is just so happy to be riding in the car (16yo) he does not care about the crunching in back when his brother is in the front seat. Yea people must had been smaller back then.