Remember that anti dive geometry is related to the center of gravity of the car and the angle of the upper control arms. So of the front end is put into another car with a vastly different COG, then that could do it alone.
With the lever arm shock/upper control arm combo I can't imagine the angle of the upper arm could be changed too much without putting the kingpin in a bind.
I am sure the problem has more to do with bad valving or improper or missing shock oil like everyone else has pointed out. I have installed a few upgraded valves in MGA's and MGB's. It is a pretty easy job and made a nice difference.