Smoking after oil change (long) Ok this is goin to be kindof long so bare with me. I purchased a cobra clone from a member of this site with all the bells and whistles including a built cobra engine about a year ago. The motor has forged enternals 04 heads hv oil pump with billet gears etc. It has roughly 30000 miles. Shortly after the purchase I do the routine things I normally do just because that's the way I am. I install a thermostat new plugs (tr6 with same gap that's was in it) and changed the oil. I also deleted the pcv and installed a breather tank for each valve cover. The plugs I pulled out looked good. #2 was a little darker brown that the others but by no means in bad shape at all . The previous owner told me he used castrol gtx. I put in 7 quarts of 5w30 or 10w30. I can't remember because I've been thru a few weights and brands since then. Anyway when I first start the car after all this I get a big puff of blue smoke. Now it never did this the 3 weeks I had the car before the things I did to it. But I also read that these motors do that from time to time so I didn't think much of it. Pretty much everytime I start the car after that it does it. It will smoke when I rev it in neutral too. WOT there is also some smoke but it appears to be black. Normal driving it doesn't seem to be smoking except for leaving a stop light or if I let it idle for a long time but I haven't had anybody follow me. If I hold the throttle steady and "clear it out" it doesn't seem to smoke that much after that. I decided after a few weeks to pull the plugs. # 2 3 and 4 have some oil on the threads and tip. It's not a lot but plugs are pretty black. #2 is the worst as it appears wet on the tip. All the other plugs look fine. No I'm a little worried but I continue to drive the car and experiment with different oil brands and weights. Over the next several months I try rotella 5w40 and driven fr20. Smoking does not stop. I contact previous owner he says it was castrol gtx 5w20 that he used and that it didn't smoke or use oil with him. I recently put that oil in and I still get smoke. It also appears that it is burning some oil too but I can't tell how much because I've changed it so often over the course of 900 miles. Now over this time period I will pull plugs 2 3 and 4 to check them. They will sometimes look like they are clearing up. Other times they look black and a little wet. The car still pulls strong and runs fine. I have not done a compression or leak down test yet. Im trying to understand what is goin on with this thing. Sorry for the long post felt I needed to explain what I have experienced over the last year. Anybody have any ideas of what's wrong? I'm thinking valve seals but I don't understand why all of sudden after the routine maintenance.