I have a 400 engine that is stock. The heads are coded #48. WHich spark plug is the best for this application??

I am running AC Delco R45S. They are getting fouled with more gas than oil i believe. Would a hotter plug work better??

A hotter plug will help a little. But I'd be focused on the cause of the fouling. Vikki has a great hyperlink to check your plugs against. Lots of pics and descriptions. It may be at her site.

Have to search here for them, I didn't index them.

Any help would be great.

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

The "search" feature at the top of this page is very helpful.

Do you have electronic ignition? If so the gap should be wider. It sounds like your carb mixture screws could use some tweeking.

All stock. The car usually sits in the garage for the most part. Maybe 10 miles on the engine rebuild from 3 years ago. It runs rich for sure. I wanted to make sure the spark plugs are correct for the setup.

Plugs are correct. You need to adjust the carb mixture screws. Turn them out, one at a time, until you hear a very slight drop in RPM and they should be very close to correct. This is a little oversimplified but give it a try.

Can you give me an idea of which screws to turn? I am assuming counter clockwise. I have a 69 FB Quadrajet with AT. It has been awhile since I have done that and dont want to start making things worse.

Should i go ahead and change out the spark plugs with fresh ones??

thanks.

Flooded plugs usually are toast. The two screws in the front of the carb are for idle mixture. It would be good to have a vacuum gage to set these but you can get it close by ear. Counterclockwise will give you more air in the mix.

Turning them in makes them leaner, not out. The idle mixture screws are on the front of the carb, below and to both sides of the fuel inlet. But with only 10 miles on it, you're not going to get an accurate read, and it's better to be a little rich on break-in than a little lean.

You need to turn them evenly, so best thing to do is to turn them clockwise until lightly seated, counting the turns, then turn back out to the same position. If one screw is out 5 turns and the other 6, back them both out six turns then start the car and let it warm up completely. Make sure the choke is fully off, then turn each screw in half a turn at a time, listening to the RPM.

I found this on this website under the tech specs.

Model AC R-44NS AC R-45S AC R-45S (AC R-44S on All 400 Engines)
Thread (mm) 14
Tightening torque (lb. ft.) 15 - 25
Gap 0.033 - 0.038

Since I have a 400 engine,should it not be the R44S???

I checked AC Delco and NAPA. they said to use R43S.
Now I am confused.

IMO, you should try to clean the plugs (if they are not damaged i.e.chipped insulator, burnt electrode etc.)you already have in the engine then adjust the mixture screws as previously stated.

You have to fix the flooding problem before worring about new plugs.