Good morning all. I have a few questions to ask. I'm running a 350 bored to a 355 with a weiand 144 blower 950 holley holley 4 bolt heads and headers. First question is I'm running autolite 3923 plugs and so far all the one I'm able to remove are burning fine. Just old. What is the difference between a hot or cold plug and what would these be considered ? Next question is. How do you get the plug out if you can't get a socket on it, because the headers are in the way? And last question. How do you get to the back bolts on the headers to tighten them? I have 2 loose header bolts and I got a 7/16 wrench on one but the other is buried in the on the right side. Also to me a wrench doesn't seem like the proper tool to do the job either way???? PS The reason I'm pulling the plugs is because I think I'm getting a misfire when she warms up. But I'm having trouble deciphering if it's the lobe from the cam or the plugs. Ty Jim