Using Dan Case's numbers, I ordered a complete set from Summit, and the individual part numbers from Rock Auto. Summit's came in a Cloyes box, R/A's in a Melling box.
The part numbers cast into the gears - crank and cam- were the same. And, neither crank gear is for a 289 HiPo with the front counterweight.
Not to flog a dead horse, but rather to aid others down-the-road, but when supplying "Dan's numbers" to the two mail order/internet sales giants, what did you get?

Apparently not those numbers, as I stated previously the Cloyes numbers S350 & S351's are and have been for some time obsolete (and I contacted Cloyes today just to be sure they had not been re-instituted) , but again as I stated previously you can still get the chain as it fits other than the H.P. applications.
And the same is true as far as Melling is concerned; I believe (

) their numbers of these would have been S406 cam gear & S431 crank gear (both obsolete) with a S358 chain being still available.
But I did realize that if one calls Summit (as I did!) and asks of the two N.A. Cloyes numbers, I was told first that they were "not available", buuuut, ............"we don't have them, but we can special order and drop-ship from the manufacturer", just give your credit card information!

And at Rock Auto on line, one types in the numbers, and the screen pops up with a different number "placed in your basket" for check-out! They apparently just substitute the next closest product that "might fit", and perhaps as in the case here you won't send it back (you paying the freight to return it of course)!

In either case you'd get most of your monetary investment returned (sooner or latter) but these corrupt marketing schemes also cheat the honest retailers, who particularly when knowledgeable enough to advise one that the correct item is "not available", are then not rewarded with the sale of what might be the "as close as it gets sale", with the insight of possibly:
So, I had a very famous (in the Northwest Indiana area) machine shop take 0.150 off of the inward side of the crank gear. AND, you also have to accurately drill a hole of 0.125 in it for the locator/drive pin. This is a hardened gear. You are not going to drill it with that harbor freight drill bit.
So, every thing fits and is in alignment.
Trust me , you DO NOT want a chain with less play. The "slop" you note has literally no effect on performance BUT too tight of a chain WILL take out the front cam bearing and #1 main bearing.
+1!
Scott.