Dive bombing is all a matter of practice. I hit best when in a 38, only because thats the plane I'm in most often when I have bombs. For me an ideal run is to come in over the target at 5kspotting the target off of one wing tip or the other by rolling and using zoom. Once I know which target I am going for I roll in and point the nose down at a 45 degree angle, center the target with it on the lower edge of my site glass, ease off the stick ( no G's) and drop from 3k and pull back out.
No ack to worry about and I almost never miss. GV's I do about the same, but I will go a bit lower to make sure of my aim. If the dive is shallower I let the target pass under my nose before I drop, and if the dive is sharper I put the target closer to the pipper.
The practice comes in to let you know how much you adjust due to the dive angle.