i had a bit of a mess around with a ke20 diff housing on the weekend, i used ke30 jap axles in a ke20 jap housing, and i used ke38 borwarner drums, will be a monster diff, ke55 drums should be enough for your car, they look to be as big or even bigger than the drums on the rear of a mated datto 1600, he runs a big L20 and it has no troubles pulling up,
this car is looking really good, just need some bigger wheels, i hate 12" mags, i had them on my first ke20 when i bought it, put on silver RX2 wheels instead
GL with it
cheers james