4.3L vortec. Which spark plugs?

[fourwinnsdook]

Ok, i have an 87 4.3L engine that i recently put vortec heads on. I did it more because the old heads were worn out so i found a manifold and 2bbl carb off of a 2004 marcruiser to put on it. I am now trying to find the best plugs for it. All of the auto 4.3 vortec engines call for platinums is that right. Please help!

 

[Bondo]

Re: 4.3L vortec. Which spark plugs?

Ayuh,...

The MR43T was the plugs for Chevies for Years,...
The Vortec heads take a longer plug,...
MR43TS or maybe it's MR43TL,... Don't remember...

Somebody will be along that knows for Sure...

 

[TilliamWe]

Re: 4.3L vortec. Which spark plugs?

It's MR43LTS The Vortec V8s use them too. The "L" is for "longer reach". Which Vortec heads need.

 

[fourwinnsdook]

Re: 4.3L vortec. Which spark plugs?

Thanks guys! i found them at NAPA! the plugs work, but i have a bad miss. i checked compression and it's way off. i never adjusted the valves after i put the new heads on. I'm guessing that's a big deal?

 

[Don S]

Re: 4.3L vortec. Which spark plugs?

The valves aren't adjustable on the Vortec heads, you just torque the nut down to 20 ft lbs.