Iím looking for plug recommendations.
400SBC (bored .040), mild cam, Edelbrock 1406, Heads are casting # 3973493 (76cc, iron, stock from 70-76 400). Recently rebuilt motor and trying to get running. Have had the motor running in 5-10 second stints. It seems to run well (as I recall from before the rebuild)...and then it dies out. I get the feeling my Carb is flooding the motor, so I recently added a fuel pressure regulator. Since the motor still didnít stay running, I checked the plugs again and found a couple concerning issues:
1) Plug #6 gap has magically reduced from 0.045 to approx .010! I assume I purchased plugs with too far of reach, and the piston or valve smacked the plug tip closed?
Hereís a pic of old and new plugs together:
Doesnít take a genius to realize the new ones are longer reach, but still not 100% sure which is correct. Iím really hoping someone has a good plug recommendation (#) for my application.
2) Plug 7 and 8 had fuel in them upon removal. This happened a couple weeks ago after initial installation. Took them out, dried them all, aired the motor for a few days, and installed a fuel pressure regulator. Reinstalled plugs, tried 6-7 start attempts, car ran for 15 seconds total, then removed and noticed the excessive fuel. Both header tubes felt just as warm as the others.
Not sure if I need to rebuild the carb, or if I should try a Holley 750 (4160 I believe) that Iíve never tried and has been sitting on the shelf for 5 years.