I'd be leary of tightening that puppy down with out having it welded - it's sure to get worse, and jb weld ain't gonna help. If you have it welded, probably ought to have them check the mounting surface for true afterwards - they may need to take a bit off to true it. And advice to everyone considering the manifold -- ask ahead of time if it's cracked there or back on the #4 similarly. Mine was cracked and welded - nice repair job. But the seller told me about it and sent pics.