MD8 = 700R4 / 4L60 (no 'E')
M30 = 4L60E
M32 = 4L65E (4L60E Heavy Duty)
MD6 = 4L65E (what is 'PTU'?)
M70 = 4L70E (Super Duty) (somebody with a TrailBlazer SS, please check their RPOs?)
MT1 = 4L80E
MN8 = 4L85E (Heavy Duty)
MYC = 6L80E
MYD = 6L90E (Heavy Duty)
M5U = 8L90E
MQE = 8L90E with 'improvements'
MF6 = 10L80E
MX0 = 10L90E
Please note Fless' corrections below.