[MillerBuilt]

Forget about the actual differences between the two rears. Your car and or application will determine your pinion offset.

In your case, a 1969 Camaro has a factory offset of 1/2" to the passenger side. So unless you have altered your engine/tranny mounts to locate otherwise, you will build your housing (9" or 12 Bolt) with a 1/2" pinion offset to the passenger side so that crank, tail shaft, driveline, and pinion are in one harmonious line.

example scenario: 54-1/2" desired wheel mount surface with 1/2" pinion offset to the passenger side.

PC = Pinion Center
WMS = Wheel Mount Surface

PC to WMS driver side ----------- 27-3/4"
PC to WMS passenger side ------ 26-3/4"

To locate your suspension brackets you would make a mark on your housing at 27-1/4" from either end, which would be center of your overall rear-end width, AND actual center of car. You then would work out from there per DSE instructions to place/locate suspension brackets.

Hope this helps....

Jay