This is what I have:

400 sbc AFR 180 comp. heads 74 cc chamber, comp cams ex. energy 270 hdy. roller  with 1.6 pro magnum roller rocker so lift is about 525/532 I think .  Forged flatops, 6inch rod, 750 holley double pumper 69/70 jets, proform main body and blocks scat crank and rods, MSD 8361 dist, and 6al ignition box blaster coil....Upon first startup, seemed to be running rich but good throttle response no miss, and I adjusted carb and came down from 72/84 on the jets.  Today I bought a new set of AC delco 41-629 plugs and put in and ran for two minutes and killed it to check plugs and they were  black with that sutty look. I have my floats set to where if I shake the truck you can see a little gas run out on the side. All of the ignition is new, everythin on carb is new except baseplate, and like I say it doesnt have a miss. just seems to run rich  haven't had a chance to drive it because no pipes and highway man has been riding around lately but will get pipes tomorrow...Need help

Too early to worry, 2 minutes of running with no load on the engine is not nearly enough time to get the plugs hot enough to burn off deposits. If the engine is running without a missfire at this point the plugs are doing their thing as they should.

The 41-629 which is the new number for the FR3LS that is the plug recommended by AFR for this head. Therefore, this is a good starting point. After you get some miles on this set up you can look at the plug and decide if it needs a range hotter or colder. This adjustment, if necessary, is just to dial in the heat range to the engine's configuration and how you use it. For example a long duration cam, lots of compression and aggressive driving may want a range colder plug. A shorter cam and lower compression combined with conservative driving may want a range hotter plug, this would also be true of the first engine driven conservatively where the plug just doesn't hot enough to keep itself clean.

But you need to get out on the street for a little while before you'll need to cross the heat range bridge. Also, it's not unusual to foul a set of plugs while setting up a motor, a bit too rich for a bit too long can soot them up to where they're shorting out and missfiring. Then the best choice is to put a fresh set in. But as long as they're firing, I wouldn't worry about them being dirty at this point.

Bogie

Thanks Bogie, just got the pipes super 40 flowmaster and 2 1/2 inch pipes with h_pipe so I will try to drive asap but have to work this weekend..Keep you'll posted  

Sounds good, those 2&1/2 inch pipes ought to put some fear into the Civic crowd.

Bogie

Ok got the pipes and reset timing and drove it about a mile up the road and checked the plug and I could see where it started burning clean so when I get a chance I will put some miles on it and kepp you posted, and it sounds pretty good, not to loud or to soft, got on it one time and it really comes alive at about 2500 to 3000 grand,  

sounds good

Bogie

The magnetic pickup coil was bad in my brand new MSD 8361 distributor that I hadn't put a hundred miles on before it finally just quit.  Gettig off work friday morning and got ready to go and she fired once and went dead and I continued to try to crank her and no good.  Well I started troubleshooting and checked the firing and it was firing but yellow fire instead of blue so I thought it was the blaster 2 coil so I returned and told the part store guy to check it with a ohm meter like the guy at msd said but noone there knew how to use one, so they just gave me a new coil, installed it and it didn't work so I called MSD to get info on how to test my new 6AL box and I couldn't get the results they said I should so I went down to oreillys and purchased a new one and installed it and it still didn't start.  So I was stuck with a 259.00 box that I didn't need.  Upon playing with it in the cold at my job I came to the conclusion that the pickup coil in my new distributor was bad, and the part was 29 bucks.  Installed it saturday morning and she fired right up and I notice that she isn't running rich anymore and I think I may be a ble to go back up on jets in carb (currently 69/70) after I retune and reset timing. A person goes and buys new parts, so that they wont have to go through this and as the old saying goew you can buy parts bad these days.  I purchased distributor from summit last DEC. and just kept everything in closets until I got everything so I couldnt send it back.  300 bucks spent and a lesson well learned, and she is running better, have to get the new 373 gears and eaton locker installed soon  

Why is that all that ends well costs so much time and money? Good to hear you got to the root cause, I admit, I wasn't expecting such a problem.

Bogie

My temp hand goes up past 210 to about 220 + when I stop at  a light or slow down.  Have a new 4 core copper brass radiator and a fan shroud.  I have a little gap between fan shroud and radiater support but other than that its sealed up pretty good.  It really got worse after I installed the fan shroud, I can hear the clutch fan making that lound noise like its sucking air when I get on it, starting to get annoying.  Thinking about trying to get a new severe duty fan clutch.  Whay do you guys think.  

Got the temp problem fixed.  Now I am back to tuning and I have a 750 with proform main body and blocks.  Running AC delco 16-429 spark plugs.  After about `15 miles of just cruising I let it coll off and pulled the plugs and they are white on the very top of the porcelin and black further down in the plug.  I have a MSD pn 8361 pro billet distributor.  I was reading on the box about the different springs setup and I install one small blue and one small  silver spring which says that my timing should reach the max amount of timing by 3000 rpm.  Now for the advance stop bushing the silver one was on there when I bought it and I haven't install another, really don't know alot about timing.  I know that witha timing light my initial is set at 17 and if I go over that it clatters when cruising under about 2300 rpm.On the jets I have 69/71 and a 30 cc pump in front and a 50 in back.  Have the floats set to where if I shake my truck at idle a little gas comes out. Have Moroso ultra race wires (got a super deal on a new set) and I have a open carb plate on top of my dual plane air gap in order to use vacum port on intake. Have the 373 gears and eaton locker but not installed yet.tci breakaway stall 2400-2600 rpm, and extreme energy 270 hyd. roller 495/502 with 1.6 rockers which i think bring lift to about 525/532.  Ok guys I think this is it, so please examine and give me some tips, and if you have any questions about setup let me know

Thanks