[steves1967]

You're right on a stock, barely breathing, 100,000 mile engine manifolds are probably better. However, put manifolds on a performance type engine and you'll choke the day lights out of it. To the member with the 406 that ran better with manifolds...I would suspect that his entire combo isn't matched and the manifolds acted as a crutch. 3/4 length headers don't add much flow over manifolds, but put a full length header on the engine and watch it purr!!