Thank you DD for putting my name on this ^^^^^^ . We actually came up with improved rotor design for 2020 all made right here in the USA. The cap you are looking for and WANT should be brass terminals underside and on top. Meaning brass all the way thru. Also there is 2 different versions of rotor designs to use for the EST distributor apps. The 454 and the 502 used the EST set up. Also extremely wise to buy a new coil. for the coils here again for 2020 I have an USA made coils. Important info about coils - you have to match the primary and secondary resistance of the coils per what the ignition system was designed for. Everything I have is all done & made here in the USA. Since everyone here supports America why buy from other countries ???


If anyone has questions about my coils ASK VOODOO ROB he has my specific coils on his Merc racing 700 sci engines. You can not get these coils anywhere else. NO BS. Yes you can get the look a likes but they are not these coils that I have made.


Also for the record will add more info about caps and rotors ---- the T bolt IV and V cap and rotor for Merc thunderbolt ignition - I only sell Merc brand, cap and rotors --- why because they are made in the USA by merc themselves in Florida. They do make the best cap and rotor for the THUNDERBOLT ignition set up. And these are brass all the way thru for terminals on the distributor cap.

Why are the coils recommended to be changed? I haven't heard of that before now. Only cap/rotor/wires/plugs.......

Thanks.

Thousands of good coils are tossed every year and mostly because there cheap and easy. Have only seen a few that really need to be changed

If you work on lets just say 300 boats per year. You will find bad coils more than enough no matter of the ignition set up.


So let me ask how is anyone testing coil output to determine if its good or bad ?? And coil output spark energy ?


Also for the record a coil that is not warm with heat can test good a lot of the times.


Also the oil filled coils go bad all the time as the oil seeps past the inner tower structure. for a jist of info.

thanks for the information