The shock mounting faces on the uprights were overhanging by around 1mm before they were machined to fit the Williams shocks. By that I mean the shock mounting faces were wider than the stucture going upto it... We take 2mm off each side, as the Williams shock is 4mm narrower than the 172 item. That meant the shock mounting faces are now 1mm narrower than the structure leading upto it. When you compare a 172 upright to a Williams/Valver upright, it is generally lot bigger/fatter in its construction, to which I assume is for the extra weight of a 172 (200kg+ over mine), and/or because of the larger driveshaft/bearing setup. The 172 upright is probably still a lot stronger than a Williams/Valver upright even its machined (2mm each side) state, due to it having more material everywhere else. Ive had no worries about it because of this, and its been on the car since October 2008, covered 15+ trackdays and never had a problem...
When you compare a Williams stub to a 172 stub, it is narrower in the first place. I have taken the 172 stub down to aid with clearance, and because I dont see any problem with it considering the Williams/Valver/Mk1 item is thinner in the first place. The only reason a Williams/Valver/Mk1 stub was not pressed in is because the spline for the driveshaft is smaller, useless for me as im running 172 shafts.
The holes were drilled out to 1/2", basically just removing the thread. 1/2" is 12.7mm, what exact hole size does an M12 thread usually have? Must have only removed 0.2/3mm from each side of the hole if that when they were drilled out...
I could have got an eBay kit, or one from elsewhere etc, but ive heard about the studs winding out after a few trackdays time and time again on quite a few different forums. It always seemed to happen when people had done a trackday and come to change back to their road wheels, they would undo the nuts and the stud would come out with it - something I didnt want to be happening after the f*cked threads Ive had before! Im sure Andrew will reply and comment on the 'screw in' kit he recieved for his 5 before he did the press stud conversion if he reads this, the studs were pretty much monkey metal!
Going from that im quite confident that it is still just as strong, if not stronger than a Williams/Valver hub. Fair enough if any serious heat had been involved like we mentioned a few pages back (Welding or whatever), the metals properties may have changed/weakend etc, but its had nothing like that near it. The stubs were taken down on slow cut, and the uprights machined on a mill - nothing anywhere near the level of heat welding would generate. I went ahead with the idea as Andrew has ran it on his 5 racer, with the same press studs, same width machined stubs (his were Laguna hubs) and full slicks - Im sure if he'd had any problems he wouldnt have recommended the idea to me