I have fitted an AE86 6.7" TRD 2way LSD centre into an H165 diffhead.
-I had the centre machined to allow the H165 crownwheel to fit over it.
-Sleeves were made to fit inside the LSD centre crownwheel bolt holes to accommodate the space left from the narrower OD H165 crownwheel bolts.
-Brand new bearings for the AE86 centre were used, with the cup OD machined down (on an expensive specialist machine) to fit in the H165 bearing housings.
-The LSD centre was machined inwards on the side bearing journals to allow for shims to be added to adjust side bearing preload and align teeth mesh pattern (shims were fitted between centre and bearing cone, advised by diff specialist next time to have shims fitted on outside between diff housing and bearing cup).
-Diff assembly was assembled with new pinion bearings and seal, and adjusted to specs (diff specialist fitted a solid pinion spacer as diffhead to be used in an S110 Silvia disk brake rear end in an early 79 Sunny B310 with CA18DET and his concern was the extra torque the diff would need to handle
*** All machining was very minimal and done professionally. As there was concern over removing material and creating weaknesses we looked into the safest and most functional way to achieve the strongest most reliable result worth the effort***
I have another diff to finish and assemble, I could look into some pictures and a technical thread if people would like?