How the F do you get to the bell housing bolts?!

My '69 is tight too. But there's always a way. On mine, someone smashed the seam flat between the firewall and the floor in the tunnel area just to get another half inch wiggle room. You can always take out a motor mount and let the motor drop down to gain a little too, if jacking the trans with the trans mount loose isn't enough. I think I get all four top bolts with a wrench..... a box wrench, no open end would fit.