I know the exhaust holes are helicoiled but are the rocker stands as well?

Yes, my "super stealths" are so I would assume the "regular" stealths are also.

Yes, they are.

I've had my rockers/shafts off multiple times with no issues.

I think you'll find only 3 of the 5 are heli-coiled...... Same as the Ede heads.

What's the purpose of this; is there any advantage?

Aluminum tends to stick to screw threads unless you're careful. Helicoiling the holes puts a steel thread in contact with your bolt or stud. It also gives a larger area for the threads to pull on the aluminum, because the effective diameter is now that of the threaded insert's diameter.

I believe the FAA requires all aluminum threaded holes to be Helicoiled, I'm sure someone will tell me if I'm wrong.

Some manufacturers claim their aluminum is strong enough the threaded inserts aren't necessary. That could be true.

R.

and you will cry when you remove your bolt and the threads come with it, or the bolt/fastener breaks. you should helicoil, or the thread insert type of your choice, on ALL threads in aluminum that are mated with dissimilar fasteners [in this instance, the fasteners will almost always be a steel alloy type] that are under pressure, will be frequently removed for "x" reason[s], or where you want to maintain a consistent torque value[s]. just something i learned in my 42 1/2yr+ career as a machinist. i have used helicoils, timeserts, keenserts, and variations thereof, in sizes from 2-56 [those are a LOT of fun to install !] through 1 1/2, plus pipe threads to 2". lots of guys get away without using these inserts, but i have repaired way more than that because thread inserts were NOT used. just my experience and opinion, your mileage may vary.......

^^^ Good to know (& I am going to check the rest of my super stealth rocker saddle threaded holes) to see if all of em are HC.

Thank you; that's good information!

Heli-Coils work great. However most aluminum heads are not Heli-Coiled. My Indys are not (except for repair). Factory aluminum heads are not either. So why are these Done? Damage? Metal quality?
Doug

factory items are not helicoiled for two reasons. cost being #1, and #2, factory stuff is assembled in the assumption that it will be a one time assembly. if and when it comes time for repair, it will usually be replaced. helicoils [or other types of inserts] are the ONLY choice for items that see extreme or heavy duty usage, and/or are frequently tore down for inspection or wear repair. this is to insure the quality of threads in the parent material, in this case, aluminum, will always stay as intended. if any damage does occur to the threads, the inserts can be changed out without worrying about the integrity of the original insert threads in the parent [aluminum] material.
this does not by any means, suggest you can't disassemble parts that do not have inserts, and ruin the threads. this happens all the time, and threads stay as manufactured. however, if done a lot, or electrolysis between the differing material happens [steel bolt, aluminum threads], the threads will wear out or tear, and the bolt can break or pull the threads out. anti-seize is your best friend in these [infrequent] situations.

I just (re)checked my super stealths & the middle & end saddles are helicoiled but the other (2) with the oiling passages are not & the threads in those (2) are recessed way down from the face of the saddle as opposed to the other three where the threads are up close to the saddle & you can see the end of the helicoil wire in the inserts.

RR, in my opinion, the machining process used on the super stealth's could incorporate a helicoil in the oiling passage saddles, although i have never viewed, nor held a set. just my opinion, and i could be way wrong, but i'm sure they [helicoils] could be incorporated in those two positions with a little thought. at the very least, if those were my heads and i didn't want to use helicoils, i would use studs in those positions with high temp copper anti-seize on the head threads, plus whatever the stud manufacturer recommends for the stud/retaining nut threads.

I read your info above & I was impressed so I will stud those holes.

wasn't trying to impress anyone, just passing on the practices i used as a machinist during my working career before retirement, and continue to use today, so i don't get rusty ! [you know "old" things rust, right ? ]
and don't think for a second i haven't "hacked" together a repair or two [or three !] just to get something back in operation "yesterday" ! even those hacked up messes sometimes surprised me, as well as others, at the longevity and performance they delivered ! that's the reason i was tasked at work to repair items that couldn't be fixed in the "normal" fashion, or was needed RIGHT NOW.

I will go ahead & use high temp copper antisieze on the studs for those 2 saddles & on other alum apps per your recommendation.

Lot of great info, I've never used a helicoil, but have always wondered why they don't back out with the bolt they're intended to hold when that bolt is removed?

Because when unscrewed they want to expand, which forces them even tighter into the hole.

as hemi rick said. very, very seldom do inserts back out with the fasteners, although over the years using them, i have had that happen. usually, when this happens, it is because the helicoil threads were tapped improperly during the initial installation. it could be the wrong drill size used, the tap used incorrectly, such as [mostly with] it being tapped by hand, and thus not being perpendicular to the surface, or several other items/practice[s] not being up to snuff. another real problem some have, is not breaking/removing the installation tang after installation, or using a too long fastener, each discussed item causing the fastener to severely bottom out in a blind hole, and in a through hole, if the installation tang is not broken off clean, the tang remnants can snag on the fastener threads during removal, causing the coil to try to stay with the fastener during removal. on other derivatives of inserts, the locking action can be interference thread fits, locking compounds of differing types, or other means of securing the inserts, preventing the inserts from coming with the fasteners during the removal process. this, by no means, indicate these inserts can not be removed. they are relatively easy to remove with a little practice/patience. i forgot about the custom insert i made one time to fix a 4"NPT thread on a gas well meter. this insert was made from a slug of 6" round steel. the male threads were 5 1/2"x12 with a 1/4" thick flange that screwed into the aluminum body, and was retained with 4 - 1/4"x1/2" long set screws. it was sealed on the OD threads with an o-ring at the flange in a receiver groove, plus thread sealer/pipe dope on the threads. the internal 4" pipe threads were sealed in the normal manor [pipe dope]. if removal was required in the future, additional inserts could be purchased with the retainer screw holes in excess around the flange in case the original four flange holes did not line up. a new o-ring was included as well. this then became a running change to the meter bodies we made, and lasted for many years until production ceased on that body type.