Mike, the S&S carbs have indeed been used on inlines, with great success. They are available either with or without accelerator pumps. The photos shows a 261 motor tuned by Armond Orr, using 3 S&S carbs. It ran 150 MPH - in a pickup truck! Armond doesn't frequent this board, but perhaps we can talk him into a guest appearance.
We also have a club member here in Florida who is a longtime Harley rider/builder and we've talked at length about sidedraft bike carbs and how they would work on an Inline engine. S&S can be a little pricey, this guy recommends either the OEM Harley carbs or even SU's from a 4.2 Jaguar. I'm sure there are many more possiblities including Mikuni, Amal and Dell'Orto. It just depends on what you can turn up at bike swap meets. But the Harley carbs would seem to be a natural as the V-twins airflow requirements are about the same as a big inline motor would need.
