though you could really use either style cap you like

As the name implies

Chrome plated polished allen screws to assemble frame on 2002-up VRSC models

Chrome plated locktabs OEM# 7410 and bolts mount front fender on 1951-1978 FL

This is not a good idea

Oil Pressure Gauge 0-60 psi - Chrome Bar Width_32+ inches though you could really useUnder pressure? Make sure you are with these precisely reading 0 60 psi PanAm gauges. With a sturdy steel housing and liquid filled indication to protect against vibrations. 40mm 1. 57 inch diameter dial, 1 8 27 NPT thread. Check out the Oil Pressure Gauges and Mounts category for gauges and fittings to go along with this adapter.