Anybody know where I can buy a 5/16" letter R drill bit. I've checked ace, Napa, fastenal, and nobody seems to have ever heard of a letter R drill bit.
I've got a '99 Chevy 3500 6.5 turbodiesel. Is there a problem with installing the pyrometer probe on the driver's side exhaust manifold (using the drill and tap variety)? That part of the engine compartment is less "cramped" than the passenger side. If this is an acceptable area, where on the...