I've had it on the road about 3 weeks now, The engine just started idling very rough,then not at all. As I drove from a friends yesterday it would shut off at a stop sign,belch black smoke from the exhaust when it cranked. It even back-fired once while going down the road about 40m.p.h. The Motorcraft 2BBl carb was always a bit troublesome so I suspected it first. I adjusted it enough to keep the motor running but it was rough and still had black smoke from the exhaust. I thought I heard a valve tap,but found it to be an exhaust leak at the header/manifold gasket of my 2F motor. As it got dark outside I could actually see a tiny spark of flame as I peered at the header gasket area. Tomorrow I'll start again,first tightening the bolts to spec.Should this be done in any exact order? What's the lb. torque,off-hand? Are these symptoms signs of something more serious such as the gasket already blown,valve burned,etc.? I have heard that headers are notorious for such leak problems.Would I be better off just getting a stock exhaust manifold somewhere? Where would you go from here? ???