Black blast marks appearing behind tailpipe

[696969]

So, I'm discovering this black blasted mark right behind the left tailpipe these days. Only the left one. Has anyone ever seen this? It seems to have started after I installed an electronic ignition, Flamethrower coil, new plugs and wires, so maybe it's just that it's clearing out some long standing gunk in the engine and pipes with the added energy. I also have the timing advanced on my 318 2bbl by about 7º.

Either that or I guess I have an oil leak. The exhaust isn't black though.

Any ideas???

Thanks!

 

[RustyRatRod]

You might have some carbon on an intake valve or two. Try running some sea foam through it.

 

[67 coronet]

i would pull your plugs and read them just to make sure you dont have a problem with one hole.

 

[696969]

I'll have to try some of that seafoam. Probably the extra heat and energy from the new ignition system is dislodging some of it.

I will say that the Pertronix system really makes a difference!