I've got a '46 Chevy with a '54 235 in it. I did the rear 4:11 to 3:55 back in 1997. I can't say much about the 216, but the 235 has plenty or power to pull the 3:55. I run 16 x 7.00 tires and run at about 62 comfortably. I'm running the heavy duty non-synchro 4 speed trans.
If you're planning on running faster, be sure your brakes are in top shape and give a look at your front end for wear. I run bias ply tires and they can be a handful at highway speed, even with a tight front end and steering box.
David B
