I'm six two and pretty long in the body but fit in my CAV (without the drop floor option) no problem. There are some tricks to gain a little more room....dropped floors, lean the seat back a bit further, take out the slider rails on the seat and bolt it directly to the floor (adjusted for you, of course). I think I've even seen some folks mention taking out some of the padding in the seat....that seems a bit extreme given how hard most gt40s seats are anyway. But, with some of these tricks at your disposal, like Ron says, you'll fit fine in most without a helmet.