Strange ignition sounds

[Minkota]

I just purchased the truck and it is making some strange noises and I was hoping someone could help me diagnose them.

When I accelerate I hear a rattling noise coming from the engine.
When driving at a steady speed I can hear a popping sound in the exhaust (kinda sounds like popcorn popping inside the exhaust )

Someone suggested maybe try adding an octane booster to the fuel but that did not make any difference. After that fuel ran out I filled up with Non-Ethanol fuel and it still is no different.

The truck is currently set up with a small block Chevy (not sure if it is 305 or 350), it has a Carter AFB Competition Series Carb, and it has a MSD 6A Ignition Box, Powerglide Transmission

I Ordered a new set of Plugs, Wires, cap, and Rotor and they should be here in a few days.
Any suggestions would be greatly appreciated.