I agree with the different bolt size idea. If you have enough meat around your hole, find a larger size you can drill it to and don't use a helicoil at all. you can go metric or standard, depending on what you want/what's readily available.
I went through this on my 6BT Cummins injector pump. A couple of the bolt holes wallowed out from the bolts not being tight enough and the vibration (the solenoid they hold is pretty heavy). The bolt size was 6mm. I calculated that I had just enough metal around those holes to drill it for 1/4-20, so that's what I did. Helicoils are for when there is no other choice, because at that point money is not as important, and I think Helicoil knows it.
Chris
I went through this on my 6BT Cummins injector pump. A couple of the bolt holes wallowed out from the bolts not being tight enough and the vibration (the solenoid they hold is pretty heavy). The bolt size was 6mm. I calculated that I had just enough metal around those holes to drill it for 1/4-20, so that's what I did. Helicoils are for when there is no other choice, because at that point money is not as important, and I think Helicoil knows it.
Chris
