Whats the best plug, wires and outdrive upgrades for the 4.3l w/Thunderbolt ????

[woodsg]

Hello everyone Im looking to do a tune up on the ole 89 searay. I found a set of 8mm Mallory marine wires and a Merc replacement cap/rotor set. What I'm looking for is the best plug that yall have had good experiences with. I like to get some different views and stories to help with my decisions. I figured the wires would be good because they're bigger but if anybody doesn't think their good Id sure like to hear about it! Can I throw a higher voltage coil in it?? Shoot me storys, pic, and part numbers if at all possible! My parents bought this boat new in 89 and want me to keep her a float! Thanks Gus!!!



P.S. I plan to reseal and replace the ujoints in the alpha one so anything to help with that is welcome. Im looking for a U joint and reseal kit if they exist!

 

[tpenfield]

Re: Whats the best plug, wires and outdrive upgrades for the 4.3l w/Thunderbolt ????

When I bought my boat recently, the surveyor told me that the GM-based engines seem to run best on AC/Delco spark plugs and do the worst on Champion spark plugs. NGK would also be reasonable for a GM engine.

So, I bought AC/Delco. Probably you should try them for your engine.

 

[achris]

Re: Whats the best plug, wires and outdrive upgrades for the 4.3l w/Thunderbolt ????

Getting AC plugs in this country is like trying to find polar bears in Patagonia... So I've always used NGK, never had an issue with them. I find they last about 250-300 hours, then the engine starts giving the slightest surging at about 2,000-2,500 rpm... Time for new plugs...

Seal kit for the drive-shaft housing... 26-32511A1
Seal kit for the gear housing.... 26-33144A2
Unit-joints... -75832A3 (you should be able to find an acceptable equivalent in a good car parts shop)

As far as seal kits go, I prefer to remove all the seals and 'O' rings and take them down to the local seal shop, and have them match them up, way cheaper.... You may also find that some of the seal surfaces are grooved. Look into speedie-sleeves for the best way to solve that problem.

Chris.....

 

[81 Checkmate]

Re: Whats the best plug, wires and outdrive upgrades for the 4.3l w/Thunderbolt ????

Mallory....Makes good stuff, i have their whole ignition set up ( Dist,Cap,Wires in my 350/260hp boat ) My Thuderbolt IV craped out 2 yrs ago and replace it with the Mallory set-up....... no issues thus far.

Knock on wood!

 

[woodsg]

Re: Whats the best plug, wires and outdrive upgrades for the 4.3l w/Thunderbolt ????

Thanks every one. I use AC Delco on all my gm's. Good numbers. Anybody know the number for the plug.

 

[Don S]

Re: Whats the best plug, wires and outdrive upgrades for the 4.3l w/Thunderbolt ????

AC MR43T spark plug.

 

[04fxdwgi]

Re: Whats the best plug, wires and outdrive upgrades for the 4.3l w/Thunderbolt ????

AC/Delco MR43T, NGK BR6-FS both are perfect choices. I use the NGK's and have zero problems.

I also use the JEGs 8.5 MM plug wires. WAY cheaper (about thirty five bux) than the other stuff and they are made to the exact same standards as marine plug wires.

For what it's worth, for anyone that thinks that using a non-marine labeled plug wire is a no-no, I spent a number of hours and a bunch of e-mails researching this. Here is what I got from the manufacturer when I wrote them asking that sspecific question: "I have checked, our wires are made to the SAE J2031 standard that replaced SAE J557 in 2001 ". My inquary to the USCG also confirmed tha SAE J2031 is the spec that is used in the marine industry, mandated by USCG. The spec actually adresses more to the wire connectors and boots and just touches on the basic wire construction.

 

[NHGuy]

Re: Whats the best plug, wires and outdrive upgrades for the 4.3l w/Thunderbolt ????

NGK plugs here, perfect results. I had been changing them yearly, but I might leave these in because they still look new. I forget the brand of wires I have but they are marine length (car and truck wires won't reach around the exhaust manifolds) stainless core, big fat wires. I'd say they probably are the 8.5's like you are considering. Still perfect after 4 years.
Get some wire separators to keep them neat, off each other, and away from the metal stuff where there can be a path to ground. That extends their life a little and inhibits mis-fires and cross fires when they are old and can get leaky.

 

[FreeBeeTony]

Re: Whats the best plug, wires and outdrive upgrades for the 4.3l w/Thunderbolt ????

I se the AC plugs and change them every other year.
I have 2 sets. Don't' even replace w/ new, just clean the ones from the previous year and keep alternating.
Been doing this for about 8 yrs now.