Clutch???

[Dads64]

I have '64 C10 long bed that I bought as a parts truck that wouldn't idle when I got it. It's a 6 with 4 speed and it would drive/shift just fine but you had to stay on the gas. We drove it last in December and it drove fine but this weekend after I got it to idle and run smooth, it will not go into gear. The clutch seems to be not releasing. If I have the clutch to the floor and the truck in gear when trying to start it, it will drive LOL.

Any ideas on what my problem might be??

Thanks,
Jay