[superdutybob]

I am using KRE D ports @ 10.18 SCR on a 406 with a mild HR cam. The plugs that KRE recommends are 5671A-11 which have about a .020 gap out of the box. This seems tight to me. Can somebody recommend a different plug # and or gap. This is a street only car with a standard points ignition and coil. Cam is 224/231 @ .050 and .530ish lift on both sides. Carb is a Cliff special Q-jet.

Thanks in avance!

[johnta1]

I'd gap the plug around .032/.035" no matter what they were originally gapped at.

The -11 plug seems like it would be a little cold also.

An Autolite AR 3931/3932 cross-overs to that plug.

[Geoff]

I am using NGK BCP5ES in my KRE heads. 455, street driven, just under 11.0:1 CR.
Not sure if NGK uses the same numbering system as they do here. Heat range is '5'.
You want a hotter plug in an alum head because alum runs cooler, all else being equal.
I run 0.060" gaps. Idle quality was noticably smoother going from 0.040" to 0.060" gap.
Points ign will severely reduce gap size, probably 0.035" max. If it is too much, engine will crank on a cold morning but not fire.

[SS-TA]

The 5671A-11 plug is to cold, I am running the -7 plug with my KRE heads (CR 10.4). I spoke to Cliff Ruggles at one time about the pugs he was running on his KRE headed 455, I believe he said he was running either -7 or -8.