Well one of us is a moron.

[clutchdust]

I'm fixing the AC on the c5 now (compressor took a dirt nap) and got a case of the "while I'm at its". In this instance it was pull and check the plugs since I had so much stuff torn apart already. Before I get into the details, the plugs looked pretty good, just needed to file the edges sharp and good for another 50k miles.
So this shouldn't be too hard, right? I kid you not, I had to use a 3/8 breaker bar PLUS a one foot "cheater" to break all but 1 and 2 loose. 1 I had out before but that thing was stupid tight then too, 2 I can't explain. Now the only people who have done anything with this engine since I bought the car was the Chevy dealer in Chatsworth that replaced the motor under warranty. I'm guessing it didn't come with plugs because the ones that were in there were not Delcos, so it isn't that the factory monkeys did it.
That either means the clown at the dealership put these things in with a freakin' impact wrench ***or*** I'm a moron and don't know plugs on an LS motor get torqued to 100+ lbs/ft.

 

[Twin_Turbo]

He put them in without using copper paste or soemthing on the threads. Hope you did this time and yes, some people tighten the spark plugs down waaaay too tight

 

[clutchdust]

Yeah, I wondered about that. I thought either a copper or nickel paste would be a good idea but don't have any handy. Car is still pulled apart so I will pick some up today and make the correction.

 

[Twin_Turbo]

Also, check if they used gasketed or taper seat plugs, some alu stock heads on gen 1 engines (specifically L98 alu heads) can use those, the gm heads were drilled for a taper seat but can also use gasketed. I'm pretty sure the later stuff can't use the taper seats and they will pull real tight if used. I'm certain the LS heads are not set up for it.

 

[clutchdust]

That is a concern because I thought for sure the plugs would have a compression washer but these didn't. They looked a lot like the ones I use in my iron head c3. The weren't obviously tapered, and I did look at the threads, but I just can't imagine the PO had the wrong plugs put in. He had LAPD install a Paxton and do all the work so I'm reasonably sure they did it correctly. I think the problem was the dealership monkey, but I probably shouldn't bitch if they managed to get a dealership to warranty a motor that was blown.

 

[68/70Vette]

Would molybdium disulfide be a good choice? Is there a concern that using a copper based thread lubricant would result in corrosion with aluminum? So far I use a lot of moly.

 

[mrvette]

I have yet to put anything on any plug, iron or aluminum head....never had a issue either....course I don't torque them down with a 3/4 drive impact either.....:bounce::cussing::smash: