no bottom end

A dual plane intake manifold will help you a lot.

Spdloader

One of the joys of overcamming an engine. Your problem sounds characteristice of overcamming. If the cam gives it a lumpy idle, it probably won't be much fun to drive or pull anything in a truck or heavy car without a short geared rear. You need a cam designed for torque in a truck unless you are making a few other changes in the powertrain. Exactly what are the specs on the cam?

One problem with lumpy cams and stock Ford & Holley carbs is that the vacuum at idle drops below what is required to hold the power valve closed. For example, your power valve may be set to open when vacuum drops below 6.5 in/hg. If that cam makes the intake vacuum drop below that, you have raw fuel dumped. Put a Holley power valve in it with a lower spec - 5.5 or 4.5. They would be marked as "55", "45" etc stamped on them. Check any speed shop (if you can find one).

Also, you can usually get more torque from a cam by advancing the cam timing. Your cam gear may have a provision for advance/retard, or you may have to get an offset crank key. Try 2 degrees advance. Texas Parts Guy

The "loap"in the cam is caused by a high duration cam which will allow the valves to stay open longer when this happens the intake and exaust are open at the same time (overlap) thus causeing the loapy idle the larger the duration the more overlap. If you check your tach you will find that it idles higer than it would with a stock cam.If you want more low end power re cam to a cam without so much duration and get one with a little more lift than stock.

Tell it to the OP. I have a basic grasp of cam design and effect.