OK.
Was NOT able to buy OTS the 1/2" drive 11 MM 6 pt impact socket I wanted, (Looked at several places in NoVa) but Sears did have a 12 pt. Which I bought.
Here is the block waiting for me to have a go-
block, waiting
and here is a comparison of the new stud and old bolt. If you look closely you can see that the stud is just slightly longer than the bolt.
headbolt (top); ARP stud
As I expected, there is a high degree of variability in the torque of the existing TTY head bolts. So far, I have 6 out and replaced, with one that I tried but failed to remove with an 18" breaker bar, the 12 pt socket aforementioned and about 200 pounds of pull. That one will wait for the 6pt impact socket. Some I was just barely able to start, and others came out with almost no socket marks and with relative ease.
This one was very stubborn:
old bolt
The sequence is fairly simple;
-Remove the old bolt;
old bolt coming out
-clean the hole and inspect;
-Gently lower the clearing tap, carefully start it, and clear the hole all the way down. This should be a two fingered easy task. (One of the aluminum holes in the head was misbored slightly and I could not get the tap to start into the CI block, so I skipped this step on that hole.) Some folks do not bother with this step, but I think it helps get full engagement of the threads and provides more consistent clamping force over time, which is the whole point of the exercise.
Here is the tap:
clearance tap
and here is what it looks like going in-
tap started
-Once the tap bottoms, carefully remove it and once disengaged from the threads, carefully lift it out and clear the chips from the tap (I use an acid brush and PB blaster to clean it)
Here is (an out-of focus one hand) shot of the chips and shmutz that comes out
chips on tap tip
-If you are really persnickety, you will vacuum out the hole. I did not, as there is a good 1/4" of hole below the bottom of the stud.
-I do not want these to be permanent, at least not yet, so I used black ultra RTV on the coarse 1.75 bottom threads, and ARP lube on the finer 1.25 upper threads, both sides of the washer and the washer face of the nut.
Here is one going in-
stud going in
-If you bottom the stud out, you will have about 2 or 3 more threads engaged than stock, and you will be short about 2 threads up top, so I ran the stud in until I was about half a turn low up top, then torqued to 100 FP.
first torque to 100 fp
Once I have all the studs in, then I will torque to 120 and then to 140 FP per the sequence in the FSM.
A couple of other noteworthy things;
-The aluminum head was deformed in some of the holes from the TTY bolt head, which measures around 0.830" and has a radiused outer corner on the lower surface of the bolt head. The holes are just under 0.900" and the ARP washers run between 0.870" and 0.875" in diameter. Some of the holes show more or less distortion; I will probably remove and check to see whether the ARP washers 'ironed out' these irregularities after I have torqued to 140 FP.
-As I mentioned, at least one of the holes in the head was drilled oddly, as the tap would not go all the way down without binding. Both the bolt and stud would go, but not the tap.
Hope you folks find this of use; if there is anything I missed or that is unclear, please let me know!
LMW