Spark plug + gapping for AFR heads

[poulrais]

Hi,

Would like to know what would be the best spark plug + gapping for a 331 stroker with AFR heads and MSD 6AL box with stock coil. I'm also running an Edelbrock RPM Perf II intake if that makes any difference.

Thanks!

 

[poulrais]

Took the current plugs out and they are NGK R5671A-7 racing plugs (Platinum V tips). Don't know anything about these plugs and they're not listed for Ford small block use. They we're installed by the guy who built this motor so I guess he knew what he was doing

 

[SHOJOE]

My 306 with AFR head uses autolite 3924's with an msd6al gapped at 0.55".

 

[BlownFiveLiter]

.054 NA

.035 forced induction

 

[67coupe]

Autolite 3924's at stock gap = 0.054"