Final solution at last!!
Dropped the tranny last weekend because the problem returns not long after I started using s13 11/16" slave. It was all good for about 1 week or so, but then I couldn't get into gear when the engine/tranny/clutch is cold. I had to shift into gear before engine start, then after 1~2 min driving with gear engage, the shifting problem would go away.
This was so frustrating to me especially stepping on the IG dual diaphragm clutch with small s13 slave was no fun AT ALL! My left knee got all sored after a month of driving under this condition... (But the clutch is grabs soooooo good though!!!!)
So finally i decided to take the hard way, dropping the tranny at my friend's shop. Here is what I found:
(nope, no flywheel bolt back out, no pressure bolt back out, nothing wrong with clutch and pressure plate!)
the one on the right is SR sleeve, the one on the left is !@#&*% sleeve
thenismoshop sold me promising it would be the correct one. It is NOT! IT IS SHORTER! This is the reason why I could not disengage my f*cking gear!
The wrong sleeve is similar/same to a KA sleeve. Here is a picture when I compare it to my KA sleeve w/ KA TOB:
You can see the SR TOB sitting on the wrong sleeve on the left vs the KA sleeve w/ KA TOB
This is a better comparison pic. The left is SR sleeve, the right is the wrong sleeve (from thenismoshop) w/ SR TOB. The SR sleeve could add ~3mm in length/thickness, which KA TOB is ~3mm taller than SR TOB
What do I learned from this lesson?
KA TOB = Z32 TOB
many people say KA sleeve + Z32 TOB substitute SR sleeve + SR TOB is true
fact: You are near impossible to buy SR sleeve anywhere in the state.
Since KA/Z32 TOB is the same, you can totally replace your SR sleeve + SR TOB with KA sleeve + KA TOB. They are the same length/thickness
PS: my car finally shifts like butter...forever!! Now i'm using exedy stage 1 and i'm able to use nismo slave now too! I miss my IG clutch!
i'm a s-chassis clutch mechanical master now...