Are stock plugs Ok with the setup in my sig? I will hopefully going live with it in a couple days and just wanted to make sure stock plugs were Ok. I am, of course replacing the plugs, but were planning to just go back with the stock ones from the Chevy dealer.

Also, on another note, is switching to a 160 thermostat worth it? i am currently running the stock one and have already gotten a pcm tune for the stock one when i fire up the 383 for the first time in a couple days, but am considering getting that changed. i can't imagine it making a huge power difference, but if it's more healthy for the engine to run cooler like that and no downside to it, i'll probably do it. any input would be great...thanks!

 

When ever you approach the 400 flywheel hp mark which you should be in your motor, going one step colder on the plug will ensure that your motor lives long and runs strong. Lean is mean but rich is safe. So find a happy point.

I run personally NGK TR-6's which are one step colder. The plugs when I pulled them are the perfect cinnomin color.

 

So do you think that using stock ones would be harder on my engine over time?

Am I able to buy the ones you mentioned at my local Autozone store for example, or would I need to order from somewhere online?

 

I agree.... when you add more than 100HP to the engine, you need colder plug. Plug selection is striking a balance between fouling the plug (too cold) and burning the elctrodes (too hot). I run the AutoLite 104 or 103 non-platinum plugs for NA operation at the 500HP level.

I had bad experience with the stock AC/Delco plugs, even with the stock engine. The platinum pucks fell off several of the center electrodes and ground straps. I've seen many others post the same problems with the stock plugs. I think an NGK platinum would be better than the AC/Delco... probably the TR6.

 

Yep you'll see a higher HP car run much smoother with a little colder plug than the stock one. I run 2 colder and it makes a biiig difference driving around town.

 

Any suggestions on where I could get some of those plugs pretty quick? I might be putting everything back together within the next day or so and was hoping to get something local ?

 

Do NOT use the AC Platinums - JUNK!

At 100k miles, I replaced the stock AC platinums. All 8 plugs were missing their pucks, gaps were over .070".

At 160k miles, I replaced them again. 6/8 plugs were missing their pucks.

At 200k miles, I replaced them. 4/8 plugs were missing their pucks. Needless to say, I've learned my lesson, and did not use AC platinums at 200k.