[78w72]

Trying to figure out a weird part# issue on some engine side mount brackets, any of the part# gurus here able to make sense of this?

I have 2 sets of brackets, 1 from a 1981 turbo 301 TA and 1 set from a mid 70's small car with a 350 like a firebird or GTO, which are the same engine side brackets as 2nd gen firebird & TA with 400/455 engine, #496892 496893.
On the set from the 301T, one side is 496893 but the other side has a different part# or its a mis-stamp or hard to read... it looks like 496858 or maybe the last digit is a 3 or maybe 6?. Could the 5 be an upside down 9 and the last digit "8" really be an ugly 3 or 2?? Cant find much searching with the 496858, 3, or 6 as last digit. But it definitely came from the turbo TA, was still bolted to the engine when I removed it. It looks to be the same dimensions but has a slightly different contour on the top edge... maybe to clear a turbo part but still same bracket?? Anyone ever seen this part#?