Finally, an update! Cash has been tight and I have been doing some other things with the car so the suspension build slowed down.
Thanks to Rusty (04GTLib) he organised for the Rallitek HD endlinks to be sent over from the USA. It is based on the OEM design but with better ball joints which are still fully sealed with boots. This design avoids noisy operation, binding or other issues such as cracked bushes, which are common in the other styles of endlinks (Whiteline racing spec ball jointed, AVO/Kartboy/Perrin style with urethane bushes, etc).
The shafts are 30% thicker but from all reports the stock endlinks are still stiff enough for a mild increase in swaybar size. The only problem I saw was that the stock front endlinks have nylon joints which easily fail even if driving a stock car hard.
After a couple of DIY mishaps fitting the endlinks (overtorqued bolt which snapped in the subframe), cross threaded bolts which could not be refitted, all the gear is now installed with the help once again of Reade at Pedders South Melbourne.
FML what should have been a straightforward job at home turned out to be an utter nightmare!
for a hoist and airgun...
I should note to others who may wish to avoid the same situation that I did, that the AVO rear swaybar reinforcement brackets are not a good fit so you have to be very careful. There are 3 bolts on each bracket, 1 which goes into the subframe (very highly torqued), and the two for each swaybar bush mount. If you undo only the bush mount bolts, the whole AVO bracket will shift due to the tension of the subframe bolt.
This means you can't get the bush mount bolts back in because the holes won't line up properly. Due to the subframe bolts rated at 175Nm, they are near impossible to undo without an airgun. Even if you do get them undone at home the whole subframe may shift slightly and you need a punch or similar to line it back up before you can do them up again.
Also, if you remove the bush mount bolts first before undoing the subframe bolts like I did, the subframe tension totally chews out the thread on those bolts as they grind against the very tight fit holes in the AVO bracket as you undo them. You will then have to get new ones like I did (M8 x 25mm, minimum grade 8 high tensile with matching washers). Do not use the grinded up bolts again as you will chew out the nuts which are tack welded on the subframe. I wrecked one of the nuts by doing so, which had to be chiseled off and replaced with a Nyloc nut.The solution? You have to undo the subframe bolts slightly before undoing the swaybar bracket bolts. Refit in reverse order. AVO could have avoided this problem entirely by making the holes bigger on the bracket and including some big washers to go under the bolts.
On road, the improvement from the new endlinks is indistinguishable, which was to be expected. The proof is really in durability and that I'm not going to worry about one of the plastic jointed front endlinks popping apart on a hard set of corners.