Thanks Michael. Good idea. I have already taped the hole for a 3/8-16 thread. What size TimSert or Heli-coil would go into that hole and adjust to use the original (which I believe is 10-24 thread).?
Chet
There are a few options at McMaster-Carr and their search feature makes things easier. Here’s a link to a search I did based on what I think you’ve stated you’d need.
FWIW, I used an EZ-Lok solution for when I had to fix a stripped hole in the bell housing for one of the clutch slave mounting bolts. I didn’t need one of the installation tools they offer. I talk about it early on in this thread:
RobY
Turned out the inside thread was 1/4-28. I’ve ordered the EZ-Lok and tool.
Thanks Rob!
Chet
Heli-coils use an oversize tap with the original pitch. Then screw in a fresh set of ‘threads’. You order the inserts and taps by the size you are trying to achive. Be prepared to have an intricate drill index handy…
… which is why one should have numbered AND lettered drill indexes.
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That’s the one! Every one of the 105 bits accounted for. Always put back in the cardboard box and hidden in the rear of the drawer!
Plenty of more pedestrian indexes for day-to-day stuff. Only pull out The Preciousss when absolutely needed.
Plus a metric set to cover all the bases
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The heli-coil sets I’ve bought came with a drill and tap. I’ve only needed and bought about 4-5 sizes common to the E-type.
Yes, Heli-Coil brand kits usually come with the tap, drill, insertion tool and 4-6 inserts. Off-brand, well, catch-as-catch-can applies.
I’ve dealt with much more than E-Types. My personal best: A Ford re-branded tractor (metric) had the original mid-mount points ruined by the PO forcing SAE bolts into the tapped holes in the bell housing. I re-drilled, tapped and installed 1/2" - 20 x 1" inserts in all 12 holes. Tap, insertion tool & 4 3/4" inserts were in the kit. Two extra insert sets and the drill bit had to be purchased separately.
I’ve got a mower that uses 5/8 - 11 Left Hand bolts to hold the blades. When when of those holes goes wobbly…
I buy a new spindle 
We helicoiled all of the aluminum parts in the satellite business. It’s a dark art.
Sorta, kind of ditto, with air cooled VW blocks. Part of every engine rebuild that my shop did on those I helicoiled* the blocks where the headsets went in. It was cheap insurance!
*(funny note: I was dictating the above to Siri, and it wrote “Gila coil”…!)
I cringed. Tapping aluminum, in general! That stuff just LOVES to snap hardened steel tools.
‘Dark Art’ For sure!