Hey gang! Just received my Mishimoto radiator today for my 2002 wrx wagon(OEM rad cracked on the top). There is a fill cap on top that will not be used, since I have the pre-7/2002 production model, and off of that there is what seems to be the "overflow neck". In the Mishi bag of hardware they supply a bolt that I thought replaced this neck. I went to wrench off the neck, since there is a 10mm at the base of it and it stripped.... They also supply a nipple for the neck I guess. Anybody have any advice here? Tried the FAQ at mishimoto.com, searched forums here. Thanks!