I put them to ford racing and ford specs I own and operate a automotive shop specs are dead perfect. I did the install the pattern was perfect. My tech did the install still same problem. Convinced that I had a defective set of gears bought a new set had another shop install them still the same problem.
Hear is what I think ford racing quit making them.. Was is due to the fact they made too much noise? And 4.30 spin a little more rpms then 4.10 I have done 4 other cars exactly like my car only they were running 4.10 and they have no problem