never seen a freeze plug other than the type I linked, and if you look at the 'full size' of Fred's linked pic, it's the usual cup you'd find at any auto parts store, just rotten and leaking grin expansion plug

I can't imagine being able to get the 'cup' side started in the hole, unless the hole is hogged or rusted out, and I've never seen one with a lip to stop it from going all the way in on a 235 [what's being asked about], maybe the 228/248 is different, but I've never seen one installed the way Fred's second pic shows

Bill

Moved over to the Passing Lane

"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir
"When we tug a single thing on an old truck, we find it falls off" ~ me
Some TF series details & TF heater pics