Stock part numbers are 37-1406 and 37-1407

Both caps are same 'depth' in that they engage the cam bung on the gas tank in an identical fashion

this custom chopper gas tank stands out

Off center vent hole

and the aluminum washer / spacer keeps the squish right where you need it

Miller/ Vincent STOP Reproduction Tail Light Vendor_JRC Engineering Stock part numbers are 37-1406These custom motorcycle STOP tail lights are a reproduction of the original made by Miller which appeared on HRD Vincent and Velocette motorcycles starting in 1947. It acts as a running light, brake light (STOP lights up when you brake) and it also features a clear lens to illuminate your license plate. 12 volt bulbs are included, you can also swap them out to 6 volt bulbs for older charging systems. The lens of this light measure 2 5 8" in diameter.