I've done my search. But no real answer on this. When i placed the donor engine and trans in. i noticed it has the green 3.70 cog. my other trans has the white 3.90 cog. but that cog is fubar. My rear end is 3.90. So does anyone know how far off my speedo reading is? i hte to get pulled over for this. and it's only till i find a good white cog.

 

Solved: 3MPH under.