[Rory McNeil]

Ed, are you switchng to light shock oil in both the trans and rearend? On both my stick cars, I use the light shock (blue) Redline oil in the Jericos, but stuck with the heavy shock (pink) oil in the rearends. I have broke a couple of gear sets in the Stocker Mustang, even with the heavy shock, although the Pro gears in the Dana in my bracket car still looked mint after 6 seasons, so I am a bit afraid to switch to the lighter oil in the diffs.
As for any issues from the 2 oils mixing, I can`t say, but it is a hell of a job trying to get all the old oil out of the housing and tubes. That Redline oil sticks like wet paint! Even after sitting for months, when I pulled the diff cover, the oil was still covering every inch of the housing and tubes, as if it just finished a long run. A toilet brush clamped to a broom handle makes a handy tool for cleaning out the axle tubes. Personally, I would prefer to get all the old oil out, just because. I would be curious to see if the lighter oil is worth any ET or MPH, and if so, how much.