Sparkplugs Inconsistent

[Tom Honegger]

Friend of my has a GT 350 clone, 302 with original Shelby Supercharger. When he pulls plugs, front 4 are black & sooty, back 4 look perfect, almost like they're new. What would cause such a difference, front to back?
Thanks, Tom

[shelbydoug]

The carb is flooding. Check both front and back but obviously the front plugs are under the carb primaries.

Incidentally, what ever carb you use, make sure the floats are the solid nitrofil ones and not the hollow soldered together brass floats. Those things will collapse under normal useage. Forget about it with a blower.

[Tom Honegger]

Thanks. I'll pass this info on. Any other thoughts on this?

[2112]

Possible vacuum leak?