C7fe cam info

That's a lot of camshaft for an engine without headers. Since the whole point is moving air through the engine, anything you can do (Headers, big valves, ported heads) will help. A noted Ford engine builder once told me that it is almost impossible to screw up the flow characteristic of the small block Ford head, no matter what you do to it. (with the exception of grinding through the ports, of course.)

As far as the carb goes, I would first run the engine with a vacuum gauge and note how much vacuum the engine has at an idle. This is affected a lot by the distributor and initial timing.

The stock 715 has a power valve stamped 85, which means it opens at 8.5" vacuum. If the engine vacuum at an idle is lower than this, and with this cam it most likely is, the power valve will be either open or cycling open and closed. In any case, this will cause the fuel mixture to go rich with the tell-tale black smoke. I would try to get a power valve with at least one number lower than observed manifold vacuum. If the engine ides at 6” vacuum, get a valve stamped 45 (4.5) You want the power valve to be closed at idle, and off idle. It’s only supposed to open at low vacuum. (Wide open throttle) Use only Holley brand parts, be sure to replace the bowl and metering body gaskets with the Holley blue ones. The torque spec for the end bowl screws is 40 to 55 INCH lbs. Pay attention to these, if they aren’t tight enough you will get internal fuel leaks that mimic power valve problems.

Good luck, hope this helps.

Bill