as any body ran into this problem with the spark plug closing from 30 to 25 ? on a stock untuned 89 5.0 running 42 pound inj with blow trough mass at 8 # of boost and 18 degree of timing lock . 109 octane . thanks for any info.

 

whats the problem when closing the plug gap

 

I think he means his plugs are closing gap on their own.

Plug brand/type and heat range? Any idea on AFR?

 

yes you are corect that what I ment.

 

Detonation can close the gap.

 

With that boost, octane and timing lock, I don't know how in the heck there could be detonation. That is quite strange if you ask me. The only other problem could be if the fuel system is not up to snuff or if there is something in your cylinders causing detonation?

 

He asked what could cause the gap to close.
2 things could cause that, one is contact with the piston, the other is detonation.