I blew a heater hose the other day. I went to get a length of heater hose cut. Luckily, I was holding the old hose as the guy pointed out that the one end was larger diameter than the other end.
I looked at it kinda shocked. He was right. I mean, the larger end was swollen where it had gone bad, but it was obviously a different size to begin with.
The part number tag had pretty much almost melted, but I used my best CSI squint and cross-checked on the NAPA website and came up with...
Ford part # F37H18C266AC
or
NAPA part # NBH 10965
It's weird. On the heater core side it's a standard 5/8" diameter hose, but on the water pump size it's like 7/8" or almost an inch in diameter.
When I called the Ford dealership the guy in the parts department thought I was off my rocker. Luckily, I found one at a NAPA in town, and the guy that sold it to me was also surprised. He said that as long as he worked there they had never restocked that "weird heater hose" and he always wondered what kind of car it went to. We had a good chuckle over it.
I'm just posting this to hopefully save someone else that might have this problem later from having too much of a headache.
Very dumb design.
~e.