I was just about to post about this whistling when I read this.I just got my 292 running in my k-10 and yes at certain rpms it has a whistling sound mainly just off idle around 1500 rpm or so.I haven't checked the serial number of the engine but there's a cast on the side of the block that says GM 1970.I realize the head could be any year but it has plugs in the top of it too.I was thinking I might have a whistling header gasket......but I guess it's what ya'll are describing because the 250 that I had just bought that was bad and I had to take back to the parts house had that kind of head on it to and it was making the same dang whistling and my older 250 that didn't have the plugs in the head never made that sound.Will this hurt anything other than an annoying sound? See ya'll ......Gerald
