early 83 model JDM AE86's called GT's had a drum rear t-series diff.

they had the smaller axle bearing, and were basically a t-18 diff.

beau yates did in fact start off with a locked s-series diff, which he used at the first FLM nats he won in sydney, but then changed to a GT drum diff, which he had in his car for ages, but has since changed it to a t-18 diff, as the JDM one had a bent housing.

these early diffs were zenki.

Rick Drew has one in his trueno coupe.