Its getting a little murkier. It appears that GM used at least 5 different versions of this gadget. They vary by hydraulic connection thread. 1 is standard, 4 are metric. Internal piston bore. 2 are 3/4, 2 are 21/32, 1 is undefined. There are 3gold, 1 blue, and 1 silver accumulators. 1 is described as having the ports inverted so i am guessing this one puts the accumulator over towards the fender but i dont know that for sure. The inverted one has standard threads. I havent found any reference defining which was used where.
67RSSS......owned since 69. A basket case for most of it.