i have both a leveler,and a carb plate. i use both,dependent on room in the vehicle. the leveler usually gets real tight against the firewall, just as you are about to sit down on the motor mounts. alot of times i find it easier to sit the motor/trans in on the front hole of the carb plate(tilted tail down)sit it in,block up or rest on crossmember to take weight off the hook,then reposition the hook on the back hole,and sit the assembly in place. as for the 4 little bolts holding the whole thing up,i am a 20 year veteran toolmaker/fabricater/metalurgist, the shear-strength rating on those 4 bolts is way above the weight of a BB chrysler/727. believe me.