If the top of your banana bracket is that far rearward it tells me that the upper link is adjusted long which makes me suspect that you have
the pinion pointed upward (i.e. front high). Once again when we speak of pinion angle we are referring to the pinion shaft
relative to the transmission's output shaft. When determining pinion angle the driveshaft does not come into play---you can leave it on the workbench, and in fact if you follow my method method for measurment described below it will be easier if you do just that
Don't get caught up or confused on any thoughts of horizontal. Think of it this way; when looking at the car from the side if you were to project one line from the transmission output forward and another line from the pinion shaft forward with your pinion angle at zero they would be parallel. If you put any angle to the pinion the two lines are not parallel and would get farther apart as they go forward.
If the pinion were to be angled UP (relative to the trans) it's line would be above the output line; if it were angled DOWN the pinion line would be below. Below is what we're after.
Clear as mud? Maybe a visual will help. Here is a quick drawing I made when this topic came up again on the other forum a week or so ago:
Doesn't matter whether the rear end is above or below the output centerline; 2 degrees down
in relation to the trans output is 2 degrees down either way. Need more? print this image and then rotate the paper so that the line through the engine is pointing up or down left to right...see how the line through the pinion still remains pointing 2 degrees downward in relation to the line through the engine?
My method for ease of measurement:
Set ride height then put the car on jackstands so that the axle is loaded. We don't care if the frame is dead nuts level; we're only going to look at the difference between output shaft & pinion. We know that the crankshaft and trans output shaft are parallel therefore the face of the damper/ crank pulley is perpendicular to the output. We also know that the pinion flange face is perpendicular to the pinion. See where I'm heading? For me it is easier to get a good measurement with the magnetic angle finder by reading vertically on the crank pulley/ damper and pinion flange rather than trying to work with the horizontal shafts themselves. Once you can see the two angles you can then calculate the difference. Generally with these cars
we want the pinion down ~1-2 degrees the input is pointing down in relation to the transmission output shaft. Reason being is so that when the axle tries to rotate it's input upward under accelleration the pinion angle becomes less. This rotation is especially more pronounced on a 4 link car using the soft rubber bushings in OEM Mustang arms vs. a 4 link car with poly bushings or a 3 link with polys in the lowers and the solid upper link.
Hope all that helps!
Jeff