Most customers do not choose 750's,(since 600's work super on even moderately pumped up street engines) the few sets I've done using 750's (mostly on big cammed/compression or big stroker race engines) have had no reported problems. That being said I leave no stone unturned when I build these carbs, I do a 100% tear down whether new or used and process them as I would any other carb I restore, this even includes throttle shaft bushings. If they did have a problem to begin with I likely eliminated them in my normal process. This is the last set of 750's I did (this month).

I believe EB had a bad run of carbs recently (not sure what parts were bad), but based on the numbers I've seen for sale at several shows recently as "factory remanufactured" it must have been a pretty big issue, and it didn't just include 750's. I think EB reccognized and tried to take back as many as possible and repair or replace them to put the problem behind them. Most of the cores I use have been in my inventory for several years now, I'm guessing they are "pre-problem" examples.