1965 352V8 very rough idle with back fires

[Himi52]

The truck was running fine going to the store. It started running a little rough. I came back home going on the side streets and it quit several times but started right up. I started it up couple days later and it was very rough and at a high idle it backfired several times. Think it could be a timing issue? Had the carburetor rebuilt. New plugs and wires. Thanks for your help