3rd=4th=5th syncro?

After rebuilding my AX 15, I think I may have mixed up the 3rd 4th and 5th syncros...here is why:
When I TRY to down shift into 3rd, I can't get in gear unless I touch the 2nd gear position, then slide into 3rd...My thought is that the 3rd gear syncro is too small (cause when it came time to put the 5th gear one on, I had to modify it a little and grind it down ;D). And to explain the action of first moving into the 2nd gear position, but not shifting into 2nd, actually uses the 2nd gear syncro to slow the shaft down so I can shift into 3rd.
My question is if the syncos are actually different, why do they have the same part number, or am i just wrong all together?