Well its nice to see that it seems that you did good with another plug, but from what you said ( and not by much, just saying) you did not have stock ignition in your bronco. I am not saying that just putting a set of wires makes it high performance but it is no longer stock, just saying.
I run NGK spark plugs too. Never once had a problem. NGK is the OEM supplier for several manufacturers, so it's not like they make a bad product.
I don't know why so many people on here get so upset over a set of spark plugs. I agree to avoid all the gimmicks (splitfire, E3, Bosch +4, etc.), but other than quality of manufacture, spark plugs from the various manufacturers are pretty much all the same in terms of how they are constructed.
The only difference between an autolite/motorcraft standard plug and autolite/motorcraft platinum is the platinum coating on the electrode tips - the internals, including the copper core, are the same. The platinum reduces electrode wear making the plugs last longer.
The difference in gap between the older trucks and newer ones may coincide with the change to computer controlled dwell. This may generate a hotter spark than the older models where the dwell was controlled by the TFI module. .050" seemed to be a good compromise between quick starting and better performance/fuel economy.