I thought I was the only one to have this issue. It doesn't seem to be a commonly discussed issue.
What year is your 4runner? I have a suspicion that only 96 and the first half of 97 are affected by this. The intermediate shaft part number changed at that point.
My play and noise was in these u-joints also. It is a terribly expensive part at the dealer so I went junk yarding. It took me 4 to find a good one, they all had play in them. If you are like me in the earlier models a post mid-97 will not fit. Mine is now 90% better.
Now that I have the old one in hand I have tried a few times to source u-joints for it but have had no luck. Let us know what you find out.