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Any Vortec 350, 383, LS1,LS2,LS6 or 4.3 Vortec Owners

Waterthunder

Waterthunder

Well-known member
There is a major problem with the spark plugs that come standard in these motors! They are extended tip and cause a motor to detonate or pre ignite due to the ground strap and electrode being so long and sticking out into the chamber! The stock plugs are designed for fuel economy and fuel injection motors that run safely with extended tip plugs. They cause problems in airboats In an airboat the tips get to hot and pre ignite or cause a motor to run on when you shut it off! I had a heck of a time finding a none extended tip plug with a tapered seat with the correct reach. I have been using these plugs in all my motors for a few years now. I started using them years ago in my 4.3 V6 motors! I saw someones motor run on and ping for minutes and I realized I should make this public info. I gave him a set of these plugs and he said his motor doesn’t run on ½ as bad after running dry anymore. Anyway I must special order these plugs and it takes two to three weeks to receive them. I try and keep at least a hundred in stock at all times. If anybody is interested I will sell them at my cost I would just like to put in a large order and get them cheaper!
 
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The left plug is a standard plug on all GEN III and some Vortec motors! The none extended tip plug on the right is the one I use it's an NGK!
 
ive had a run on problem with my new boat since day one z383 fast burn heads9.5to1was gonna put a sylanoid to shut the butterflies wonder if thats the problem il check thanks thunder
 
I should probably go outside and just check, and I will but what reach do the Big Block L29 Vortec 7400 heads use? Was planning on not using extended tip but like I say, I don't know the reach yet! thanks for the reminder! 8)
 
Waterthunder":1hnk9t3l said:
The stock plugs are designed for fuel economy and fuel injection motors that run safely with extended tip plugs.
Click to expand...
I'll be checking under the hood of my HD 2500 tomorrow. And to think I get no better then 11 mpg now with this 489 rear end. :(
 
Normally without washers however the extended tip TIP would be good advice regardless of spark plug thread size or reach, tapered seat or gasket. If you can see the center insulator like the plug on the left of the picture you don't want to run that type of plug in an extreme aplication. Towing, marine, High performance I.M.O. You can get gaskets for taper seat plugs however their primary use would be indexing the side electrode.
 
I have a Chev 350 sb Gen I vortec, carb, with iron heads. (1997) The sparkplugs are AC MR43 LTS. The tip is not as long as the one on the left, but not as short as the one on the right.
((my life is never simple))
If I went to the one on the right could I get them in Anchorage Alaska?
 
These are for tapperd seat heads only! You can easily find the none extended tip for the spark plugs that use washers but I had a heck of a time finding none extended tip plugs for the Vortec and GENII heads!
 
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