NGK plugs

[vht]

Wanted to see what you all would recommend on a spark plug for my BBC 427. I have the thread on here Edelbrock carbs. I have NGK GR6 in it now and they seem to be to cold. It's hard to tell because they are gas fouled from another needle and seat screwing up. It has the 425 HP heads with a 650 lift hyd roller. Plus I'll have the 2 Carter 1405's on it when I start it again. I always ran NGK in the 582 on the race car but it was a tapered seat plug. It has MSD ignition on it. I thought the next hotter plug was GR5 but my parts house can't seem to find them. What would you all recommend as a starting point?

[vht]

Forgot to mention that I might have the right plug in it with a good set of carbs on it, just need opinions, thanks.

[NormS]

I've always had good results with NGK plugs. If you have good control over your air fuel ratio at idle , part throttle cruise, and full throttle acceleration, then you can use a really cold plug. We ran a turbocharged/draw through carbureted 427 Chev in an 18 ft flatbottom boat for years on one set of NGK #9 heat range plugs. The key is the fuel system's control of the fuel delivery. If you have a rich mixture for too much of the running time for any engine, hot plugs may not help for very long, and are more likely to cause preignition if the plugs gets too hot. I've run NGK #7 and #8 heat range plugs in street cars that had good fuel delivery, with no fouling.

[F-BIRD'88]

Use a # 7 heat range in a NGK.

[inline6]

Call NGK tech line and have them reccomend a plug.

[vht]

I'll get a set of BKR7E and see how they do.

[af2]

The 7 is colder...The 6 will be great when you get the real problem fixed.

[1972ho]

You should try cleaning the old plugs until you get control of the carburetor and fuel system it will keep you from continuing to buy new plugs and fouling them.

[GRTfast]

I'm having good luck with BKR6ES-11 on my 9.5:1 street big block. It's probably a tad on the hot side for my setup, but I'm not getting any detonation (can't hear any or see signs on the piston or spark plug). That plug sticks into the chamber a bit more than others, so you have to be careful that it won't interfere with your piston.

[midnightbluS10]

You can get GR5's almost anywhere. Also labeled as #2851. Summit, Amazon, your local parts store...they all carry them and if the local place doesn't carry them, they can usually have them overnight if ordered by 5pm.