cracked exhaust flange

[MisterCorn]

I've just put the exhaust back on my CSL, having removed it to change the propshaft donut and input seal for the diff. On refitting it it was blowing. On inspection there is a crack around the flange on the outer of two flanges where the manifold joins the centre section, and it is blowing through there.

Have any of you guys seen this before, if so what did you do? The exhuast itself appears in good condition so I guess my options are remove it and have it welded, see how that lasts, or remove it and fit something else. If I go that route, any suggestions on good alternative cats?

MC