That part number should be good. Comes up in two different catalogs, with or without the first zero depending on where you look. "Key, crankshaft sprocket". No dimensions or anything listed, seems to be the same for either the 2.5 or 4.0.
This reminds me of how I got one of my first 81 Yota P/U.. Back in 04 A co worker of mine was rebuilding the H22 in his parents Prelude. He misplaced the woodruff key. And told me if I could find or get him one he would give me the truck. Basically, he put a new head on the truck after he bought it, wouldn't smog blah blah. The dealer next door was a Honda dealer. Called them up, 2$ and change. Would take a day to get. Told him I found one. Was kind of frustrated when I told him how much. But he had lots of vehicles already.