From what I learned on the Four Seconds Flat web page about spark plug reading, we would need a better photo of the side of the spark plug so we can see the color change on the threads of the plug. There should be a color change on the first 3 or 4 threads starting at the end of the plug. From what I can see you only have a color change on the first thread.

http://www.4secondsflat.com/Spark_plug_reading.html

the engine runs great but slight misses on idle,

the first thing I'd do is glass bead em to clean em up or toss in some new ones & see if that resolves the idle issue

You need to seal up the intake valley pan so it won't allow oil to be sucked into the intake manifold before doing anything else
Once that issue is resolve those plugs will probably clean themselves up good
The motor will make a lot more power after fixing that also

Looks fat. Is this after extended idle or being driven? Carb? Do the mixture screws respond? 7 might be a touch cold. Back it up to a 5 and see what it does.

I ran cold plugs for a long time in the race motor because that's what you're supposed to do. Wasn't happy with it. First pass was a throw away to get the plugs clean. Started experimenting and ended up with stock heat range plugs in it. Engine was happy.

why a non-projected tip? does it have flat top pistons? a 7 may be a little cool but I think it's too rich/poor burn-tune-up.

If it shines it, the spark plug inside the combustion chamber, is oil, if it doesn't shine it has no oil
It looks like oil to me

Yes it is flat top pistons, i just wanted to try them out but the idle was smoother with projected tip

the only reason I can think of to not use a projected tip is if you have a very intrusive dome on the piston. I use autolite 3926's and they seem to burn well for driving. an ngk 6 is close to the 3926 and ngk 5's are pretty hot. i'm not an autolite or ngk fan specifically so either can be made to work. i'd try cleaning up the a/f ratio first and make sure the timing is proper. that engine should make a lot of vacuum with that small cam and big cubes. high vacuum engines don't necessarily need more jet area. big 4bbl carbs don't always mix good at low rpm but that may not be an issue here. I don't see oil use but it looks like carbon crude from a poor burn. this modern gas can get gummy and cruddy.

Thank you for your answer! I will try to put in ngk 6 projected tip and try to lean the carb a bit, i have a msd pro billet distributor now with the 6al system but im going to switch to a FBO distributor(Mopar original) with vacuum advance, i think thats better for the street. I have about 17 hg/inch vacuum at idle now but i believe that can be higher with a vacuum advanced distributor. FBO blueprinted one for me, 16 initial and full manifold vacuum that bring the timing to 30 at idle, mechanical full advance at 3200 rpm and 34 degrees.

[quote=Mopar493][quote=lewtot184][quote=Mopar493][quote=lewtot184i know Don at FBO likes full manifold vacuum for the vacuum advance, I don't; unless the vacuum is so low you need the extra advance at low rpm. I wouldn't do that with as high of vacuum as your engine is making. I bet that engine is making a bunch of low to mid rpm cylinder pressure with that cam closing the intake valve so early and this could lead to some detonation. don't be afraid to try the timed port. those vacuum units are adjustable.

Yes he told me to use it, i did a compression test and it shows 200 psi on all 8,i test in 4 pulses on every cylinder and the gauge swings up to 150 psi on the first pulse. The cam close the intake valve 64 degrees after BDC so its pretty mild for the cui's. I have not heard any pinging so far or not seen any signs of it on the piston tops but i have only drive it with the msd pro billet distributor set at 16 initial and full advance at 3000rpm and 34 degrees, so i dont know yet how it respond to vacuum advance, i have to test it some and see

......... the engine runs great but slight misses on idle, the engine have about 400 miles on it since cam break in.