Yo,
first time putting the engine into car? ie CA/SR into corolla? I think the issue is that the corolla master is smaller than the silvia one and you gotta make the master cylinder move enough fluid to displace the slave enough to move the clutch to disengage.
I had the same problem with mine and that's the conclusion I came to. I never actually looked into or researched it.
All I did to solve it was bleed it with the clevis on the clutch wound out(no thread into the clevis) and when the clutch didn't work, I wound it as far as it could the other way(thread into the clevis and touching the back of the clutch pedal arm). It may have been the other way, I don't remember. I do like my clutch to engage like a half an inch off the floor so that's how it was initially set up with the t-50 slave before I changed to nissan slave.
If that don't work, you'll have to get the toyota master bored to nissan size or adapt toyota slave to nissan trans.
If it's a nissan/nissan feel free to ignore my post.