b-300/310/500dn/510dn all use the F1899010 epson head (water based)
stylus 4400/4800/7800/9400 all use the F160010 (water based dx6?) this is the same head as the R2800, and R2400 are shown to use on some sites as well.
the epson 7700, 7900, 9700, and 9900 use the epson F191010 (the new TFP coated head). this may be the same head in the vs6740 with a solvent manifold.