I'm sure others will chime in, Bill. I've seen some GMC inline sixes with slingers like that. If I remember correctly the 228 I had was the same as the image you've posted, however it was almost 50 years ago. Chevy 216, 235 and 261 didn't have any slingers...but it has been my belief for a long time slingers would have helped with the leaking problem. The GMC (as you can see) is different in that the sealing surface is lower (where the crank is a smaller diameter) and the Chevy seals up on the flange edge...the flange connecting to the flywheel, that is. If it was me I'd clean that area as well as I could before replacing the rope seal...you'll remove the crank to replace that seal anyhow, yes? I have some rope seals I saved since I was in high school...early to mid 60s.
