Need help. I'm doing a complete tune up on my first hummer. And I can't deside on my spark plug wires. Should I keep them at 7mm or up grade them to 8 or 9 mm and spark plugs should they stay stock or should I up grade those to. Please help

 

MOVED to the H2 Section........................ where all questions about H2s go.

 

For spark plugs I am partial to NGK iridiums. Never had an issue with them.

Plug wires, you should be fine with the 7mm, but if there isn't much of a price difference go for the 8, or 9mm.

 

I stayed oem. No issues. Easy replacement too. The back left one can be a pain though!