So when I finally got around to changing my cracked header out for a new one, I pulled both manifolds off to discover 2 very small hairline cracks in my block right above the 2nd and 3rd back freeze plugs right there. It's very minimal leaking for now, but I am curious about my options here. Has anyone ever used JB Weld or something like that to fix this? I've heard cast iron welding is very hard and I would need a shop to do that. Am I SOL? Input appreciated. Also, whats the stock PSI rating of the radiator cap on these I6s?