The split port manifold that comes with the '94 truck is not only endangered, it's pretty much exclusive now. You can get one new from the dealership, but it will cost you about the same price as Blindeyed quoted for the custom. Bad part is, it's still the cast iron that will definitely crack. Doug Thorley Headers (CA) made a group buy set for the board a few years ago, but I don't know if the demand or the production faded first. If you can find someone to make you a one-off model for cheap, since you're fully rebuilding the motor anyway, do it.