Does anyone know what Chevrolets and others these might fit? I thought some of the 216 engines used them--but wasn't sure what years. Other cars they might work on? I have 8 NOS of these.

Thanks in advance for any advice!

I don't know about Amoco T5s, but '41 - '48 Chevs
used 10mm plugs. AC M8 and AC 104. Champion had
numbers to use in those Chevs. 10mm plugs were
used with other applications not related to Chevys.

Thanks for the information--much appreciated!