You have 2 studs already, correct?
Switch spots with a bolt and see, duh. lol
Oh, I suppose your gonna come at me with something like 'I can't the stock stud is waaaay too long as it is'. To which I won't argue.
IIRC when I way checking mine, now this is for a FC header mind you, M8x1.25 and 38mm long seemed to be the best fit with the least waste.
BTW I wouldn't waste my money on ARP stuff, just paying for a name in this case.
Try Dorman part numbers, 434-608 for nuts and 675-339 for studs (have them both sitting in front of me right now).
You may want a little longer stud, I don't know how thick the SVT flange is. Should be close though.