Hey guys. Looking for some help with a diagnosis here.

My 1964 F100 Styleside with 292 y-block just started running "rough" all of a sudden. For the last 5 months, she has been running smooth and strong. The carb was rebuilt in November.

Here are the symptoms now . . . Friday morning, truck ran great. Friday afternoon (after warming up the engine), I started to get a chirping/shudder on acceleration. Sounds terrible and makes this noise while accelerating in any gear. Doesn't make the noise (or at least not very noticeable) when I rev it while parked.

I pulled all the plugs on Friday (a couple were rather loose) and checked their condition/gaps. All looked similar and were in good shape. Drove it for a test run, and it still sounded rough. Had a busy weekend (with my one month old) and didnt get to address it anymore. This morning, it drove fine for the first 15 minutes, and then the sound/shake kicked in again.

I am not sure what to check first here. I am handy around a truck, but I am by no means a master mechanic. Any advice would be greatly appreciated.

Like I said, this truck ran like a dream until Friday, and now when I accelerate, I get a noticeable shimmy and the engine has a chirp/roughness. Seems to me like something with the mixture, but I dont know enough to just know this.

Thanks guys . . . appreciate your expertise! Please feel free to ask questions!