These are Delco R43S gapped at .035 in my 455, an Fa block. I probably have about 1k miles on them and recently put a new 800cfm carb on it. It now occurs to me I should probably clean them up and drive for a while to see if this is pertinent or the color is from the old carb. Nevertheless I am curious what this color would mean, not hot enough? Looks to be oily around the threads. I do have good compression on these cylinders. thanks, Steve

 

Start with a fresh set of plugs.

 

Any thoughts on the plug and the gap? I do have an HEI distributor. I've seen a lot of different recommendations that just left me wondering about the gap.
thanks

 

Use .045 for the gap. Clean or replace the plugs.

 

I took this off another old post. I will try new plugs and a wider gap but recall having read similar posts in the past when I first changed them. Any thoughts? Do you gap at .045 with ah HEI?
thanks

Just spoke with my local Olds Guru (Dan Sarvis...President of the South Texas Oldsmobile Club, races an unported cast iron head QJetted 1970 442 into the 11s, and great QJet guy if you ever need work done) and he says .030 is the stock gap. If you are using an HEI, you might want to go .035, but not over that.

 

Listen to whoever you want, rule of thumb with an HEI is .045.

 

I'll give it a shot, doesn't look right at .035
thanks

 

Original gap with HEI is fine. Going to the HEI gap will give a spark will give a larger flame kernel which can (but probably won't) cause pre-ignition/pinging. If it were mine I'd stay with the plugs in it if they are good and replace them when due with the plugs intended for the wider gap. 43 is a cold plug, if it is fouling you could go to a 44 or 45.

Good luck!!!