Rear Differential Oil Seal

[firstclass]

Hey Guys,
I noticed today that my rear differential is leaking where the driveshaft enters the differential.
I have the exact same issue as posted in this article about Previas
http://www.toyotanation.com/forum/85-previa-forum/391631-step-step-replacing-rear-diff-input-seal-pictures.html
My problem is I'm having a hard time finding the correct part for my 1984 van.
Does anyone have any experience with this fix/can help me find the correct part?
Rockauto has 3 different differential pinion seals (sound right?), which seem to the same part number as the previa. Any preferences?
Thanks!

[AD2101]

90311-38047 is the part number for all year Toyota Vans, it's available on Amazon for less than $9 so it's not an expensive part. For what it's worth, I just did this job a couple of weeks ago and it is not particularly difficult, just make sure that the nut is re-tightened to exactly (or as close to exactly) as it was before so that the pinion preload stays the same. This thread (http://www.toyotavantech.com/forum/showthread.php?885-Two-questions-for-the-pros&highlight=Differential+leaking) and this thread (http://4crawler.com/4x4/CheapTricks/PinionSeal/index.html) gave me all the basic information I needed to get the job done. I wouldn't mess with getting a seal puller, the old seal is going to be stuck in there pretty good and will get mangled coming out; just use a (very) strong flat head screw driver or smaller pry bar and just pry that sucker out of there.