[JRod_141]

They are flat. The flat seats also include a crush washer. Also a piece of friendly advice: I don't know if you've ever changed plugs before (I'm guessing by your mod list that you likely already know this), so please don't take offense if you already know this but, always use a torque wrench, and always make sure that the crush washer comes out with the plug. if the old washer stays in the well, and you put the new plug in with a new washer, you'll be wondering why it's not running so well... been there, done that

 

[JRod_141]

pic wouldn't post

 

[JRod_141]

I just did the plugs this past weekend on my Jeep Grand Cherokee with 5.7 and I didn't use a torque wrench. All came out fine with the stock replacement plugs. I watched this video first which really helped a lot. I recommend you do the same. https://www.youtube.com/watch?v=Q8iKg-UXTb8&feature=youtu.be

You don't have to use one, and personally I've never stripped a plug. That being said, it's not that I don't think I can't "feel" the right torque, I'd like to think i've been turning a wrench long enough to know what's tight enough. However, ever since aluminum heads came out, I have this innate fear of stripping the head by over-tightening a plug. Better safe than sorry, I think. May seem silly, but I try to eliminate as many variables as possible. I can be the smartest person in the world, but that does not eliminate the possibility that I still might screw it up :blockhead: