Hello everyone. I havnt been on here in a while but I have a question for you. My ignition system in my LT4 desperatly needs to be replaced. It is stumbling pretty bad. I am going to replace the waterpump, opti, wires and plugs all at the same time. My question is what plugs to get?

I know that the stock plugs are ACDelco Platinum 41-943 and have a bad reputation of the puck falling off so I would rather stay away from those. I know a lot of people with LT1s really like the NGK TR55s and they have a good reputation but they are only a copper plug and rockauto.com says the LT4 needs a NGK TR5 anyway. Im assuming because it has higher compression? And this is still only a copper plug. I have heard it is best to replace a plug with the same material it had originally.

Looks like AC-Delco part#14 is a platinum Rapidfire plug that is equivalent to the stock 41-943. Do these have the same problem with the puck falling off?

As far as NGK goes, the platinum version they have available is a 3186 {#TR5GP} G-Power
This is what they reccomend for the 5 engine code or LT4
I noticed that Delco does not suggest different model plugs for an LT1 vs an LT4
Does this make a big difference? I need to make a decision soon so please reply with any advice. I have read through a hundred old threads on other message boards and forums but most of the info is several years old and only has to do with LT1s and not the higher compression LT4s.

BTW i have most available blotons including CAI, long tube headers, no cats, x pipe, catback, 52mm TB and TB bypass and plan on doing an electric waterpump and taylor full metal jacket wires.

Thanks in advance!

 

My understanding is the only difference in NGK TR5 and TR55 is the gap, get the TR55's.