Okay guys, I really screwed up yesterday and need some advice. I found stripped threads in one of my collector/plenum bolt holes which bolt the plenum to the intake manifold. I measured the bolt pitch and found it to be 1.25. I used a dye to determine the metric size and decided that M9 was correct (in hindsite, it fit fine but had some play). I then used a M9 x 1.25 tap to rethread the hole.

Long story short is that the bolt was actually M8 x 1.25. Now I just did all the research, phone calls, etc. and nobody makes a M9 hex bolt so what should I do?

I thought about drilling it w/ a 3/8" drill bit and then tap the hole with a 3/8" - 16 or -24 tap. Is this the correct procedure? I don't have metric drill bits so I can't go to a M10 size bolt hole. Any help is appreciated!!!

Steve

I don't see why it woulden't work. Hade fun;)

go to your local autoparts store (UAP/NAPA should have them) and ask for a helicoil kit to repaier an 8x1.25 thread.

Actually with the help of my wife's stepfather, who is a foreman in a machine shop, we drilled out the hole w/ a 5/16 bit and then tapped it for a 3/8 NC-16 bolt. Worked like a charm. Thanks for the replies.

Steve