Mark,
I am now using the SMC nozzles in my IC outlet neck and don't seem to be having a problem. I am using the Walbro "Ford" pump, if that matters. Also, even though the nozzles are below the alky reservoir (WW tank), the pump is still below that level (under driver's headlight, basically) which probably does make a difference.
BTW, I finally have a pic of my IC nozzle mounting that some expressed interest in seeing previously! Just click on my website link below and then hit "page two" at the bottom. Not a big deal, but thought I'd mention it!