5.0GL-H Original spark plug

[skydiveD30571]

Anyone know what originally came in this block, or a block similar to it? I know it was an AC Delco model, but I'm finding mixed opinions as to either a mr43lts or a 41-932 or a 41-993. The originals are not currently in there. The volvo part number for replacement plugs is 21467472. I realize these are champion plugs and I have no intention of using champions, but if I atleast knew what they were I could cross reference them.

I'd like to use NGK plugs, but I can't seem to confirm which model to use. Thanks as always.

 

[Bondo]

Re: 5.0GL-H Original spark plug

Ayuh,.... What vintage is it,..?? Vortec heads,..?? how many bolts on each side of the intake,..??

 

[Don S]

Re: 5.0GL-H Original spark plug

Since it is a carbed engine and not EFI, you can use the MR43LTS or the NGK BPR6EFS with no problem.

 

[skydiveD30571]

Re: 5.0GL-H Original spark plug

Mfg 9/06 and I do believe it has Vortec heads

The label on the top of the engine that lists model number, spark plug gap, etc says "Spark Plug: 3851632" but a google search for that number doesn't reveal anything. Will the 41-993 plugs work here, or is there a reason not to use these and go with the mr43lts instead?

From another thread, it seems like 41-993's have been sold as both platinum and iridium. The local autozone carries the 41-993 and I know from looking at them that they are iridium. Is a platinum plug better for a carbed engine, or no difference?

 

[Don S]

Re: 5.0GL-H Original spark plug

Either will work fine for your carbed engine. The 993's work better with the more precise air/fuel ratios in the MPI engines.

 

[skydiveD30571]

Re: 5.0GL-H Original spark plug

Ok thanks. I picked up 993's last night but saw some websites that listed them for MPI engines. Good to know they will work here too.

 

[skydiveD30571]

Re: 5.0GL-H Original spark plug

Don I found the merc service bulletin talking about a different gap size for the 993 vs. the mr43lts. Is this just a merc thing? I've never heard of changing the gap outside of what the block mfg suggests. My block is clearly stamped .060, just curious if that changes if I use the 993 plugs.