I am doing plugs and wirea on apair of Stock 456/365hp mags
what is the recommendations one freind is saying Bosch Platinum 4 is the best plug what is the consensus

I really like the Bosch platinums. The problem is that I can't find a cross reference for the MR43t plug. Bosch's site is of no help either. I tried cross referencing to a A/C delco plug, but they don't offer a comparable in platinum either.

Klaw,
I would recommend staying with the MR43T plugs. Also if you want better looking wires you can buy two sets of wires for a 525sc motor. They are I believe 1mm larger and come med. blue in color. You can get the part numbers from mercruiserparts.com and either order from Marc or go to Watertower and have them order for you. I will give you the part number tonight as I just put the same wire set on my 454 Mag.

Dave

Thanks Dave any particular reason you would stay wit the MR43T and not go to a plug like the Platinum

I would stay with the MR43T because you will probably not notice any difference with any other plug on a stock motor/ign system and if it's not broke......... I currently run 6 psi boost into my motor and these plugs still work great. I have heard of other brands here on the board having problems with electrodes etc. I always try to stay with factory stuff if possible---buts thats just me. I don't usually ever have any problems (knock on wood!!!) .

Dave

P.S. I run an Outlaw with the name "Doctor's Orders" on the transom. I'll wave when I fly past your house!!!!!

Here is the part number for the blue Mercruiser wire set for a 454.

84-847701A7

Dave

I just noticed that I put an extra digit in the part number. It is fixed now. Sorry

dont just wave stop by