This belt tensioner should fit all transverse mounted motors but I am always surprised to find new parts that I forgot about or didn't know about so I recommend measuring your tensioner and making sure everything is the same.
This should also work for the AE86 although the diameter is slightly smaller so you may need a shorter belt. I haven't tested this but don't see why it wouldn't work.
If you want to try it and it doesn't work return it for a full refund as long as it isn't scratched or damaged.