This is just a thread to summarise some info for those of us going flex and needing ARP head studs and to discuss where to buy in Australia. I'll update this first post as new things come to light so it's an easy find for members looking for the info. Will also want help to fill in some blanks (in Red, if you can PM or post the answers or additional questions I'll update this first post for easy searching) Fastening sequence I believe is: 7 1 3 5 6 4 2 8 Quick Info (10mm): Brand: ARP Material options (in order of strength): 8740, 2000 (~22% stronger), L19, AGE 625 Number Required: 16 of each Studs: AM4.500-1LB Nut: 300-8343 Washer: 200-8519 Fastening torque for installation: 60-65ft lb (8740), [73ft lb (ARP2000)apparently non-existent?] The toyota 3 S GTE kit: Part number 203-4204 (10 studs, nuts and washers) we require 16 Quotes so far are not the cheapest but here they are below: 8740 material 10mm studs Rocket ($408.16): ARAM4.500-1LB $15.00inc GST ea. Special order ex. USA + freight AR200-8519-1 $3.30inc GST ea. Special order ex. USA + freight AR300-8343 $7.21inc GST ea. Showing 20 in stock Fabre ($556.16): ARP-AM4.500-1LB° ARP STUD 4.500 LENGTH 1.25 PITCH 1.25 PI 16 $17.70 $311.52 ARP300-8343° ARP 10mm x 1.25 7/16 12pt nut 16 $8.70 $153.12 ARP-AMW750N° ARP WASHER (Same as ARP200-8519) 16 $5.20 $91.52 Performance Wholesale Australia ($410) : This is for 16 studs, nuts, and washers in the 8740 material. contact Scott Kempthorne Log in to view CA625 and ARP2000 material 10mm studs From Sam at ARP: If the block is a M10-1.25 thread, than I only have the 8740 Chrome Moly or the Custom625 (280,000 psi) to offer. This indicates that there are no ARP2000 material studs available to suit, despite what some of the ebay and online stores claim. The CA625 stud number is: AM4.500-10LB @ ~$38.27ea Performance Wholesale Australia ($1045) : This is for 16 studs, nuts, and washers in the CA625 material. contact Scott Kempthorne Log in to view Quick Info (11mm): recommended by the geniuses due to higher strength, 11mm studs require the removal of the heads and tapping of the block to accommodate the larger studs. http://www.ozvr4.com/threads/how-to-re-thread-your-block-to-take-11mm-evo-head-studs.15338/ material info the same as above, but 11mm studs are significantly stronger @6A13TT TYPE S @trotty @LDundon @TME_Steve Massive thanks to Adam for all his knowledge and hard work taking photos and uploading of his build.