Kevin, It depends on the model and in some cases, even the year. If you are making one for a Harley Softail, for example, the panels have different mounting holes near the seat. 84-99 were the early style. From 2000 and up Harley changed the tank panel and the mounting hole position. Same for under the edge of the speedo dash- they differ. Alot of the metric V twins have similar speedo housings, so it really depends on the specific model. There are subtle but important differences in many of the tank panels. Let me know if I can help.
Tim