txs

Some of the things that were the same in all 727 based trannies, in between engineering changes. All the input shafts were the same, from start of overdrive production till the 48re, other than being lockup or non lockup. There was only one overdrive valve body, where the differences were is in the various springs and the transfer plate-separator plate. The intermediate shafts were the same. I'm reasonably certain that the A-500 trannies shared the output shafts with the 518s. Early diesel trannies had a pump housing with bigger cooling-lube circuit holes, but after a certain point they decided to make them all with the larger holes, same thing happened in the gasser trannies, there used to be 3 and 4 pinion front and rear carriers, sometime before 1990 they dropped the 3 pinion carriers. by 1990 they had dropped the 3 plate rear clutch retainers, so whether your 518 or 727 was behind a 318 or cummins, the rear clutch is the same.

txs

The reaction shaft assemblies are the same, the only difference between the L/U and non L/U is one steel ball. Indeed, if you go to a tranny shop and ask for a reaction shaft they'll ask you if it's a 2 ball (non) or 3 ball (lockup). The diesels got brass governor weights and bigger pitch pump rotors, the front carriers got 5 pinion gears, and the over drive carrier got 5 gears. The O/D clutch packs got more discs. 89 through 93 had diesel specific case but 94 and up used that case behind the v-10.