I welded mine like BJ was saying, the problem is they like cracking right where the collector is so there is usually no space to get your welder in. After about the 5th weld job I bought one of those "improved" manifolds with a banjo in the 1 and 6 port. I've put 20K miles on it, and it still runs great. Then again, the stock manifold had 120K when it cracked originally... I'd buy something cheap, the thermal expansion on the 6 cyl. manifolds is considerable due to the length of the runners. A 200$ manifold every 100K miles seams like cheap maintenance to me.