1964 Dart Owner - In Over My Head

A new exhaust manifold is >$100, and people ask >$50 for a used one on ebay. But, you can get an entire slant engine w/ tranny often for free. People try to give them away here all the time, since so many change to a V-8. If you have space, keep a spare one. If the manifold broke at the ear where the exhaust pipe bolts up, I would be tempted to bugger a fix - something like a collar that bolts over the outlet flange to hold a bolt. If you have a welder, might be easier to rig a bolt-clamp setup. Doesn't have to be super-tight, just enough to seal the exhaust.