Hello. I ordered a kit off kings motor bikes and they sent me 2 spark plugs. I just ordered a new cdi and a high performance plug wire and boot. Well the plugs that were sent with the kit are not the best. I cant seem to find a cross reference. Since im upgrading electrical i would like a new plug. The plug is a LD Z4JC. If some one knows a cross reference please let me know. Thanks P.S. Would a regular car boot work?