Can you use heads from a 305 on 327 engine block to be used in 1966 Pickup?

No, you can't directly use 305 Chevy small-block heads on a 327 Chevy small-block. While both are small-blocks, the bolt patterns are different. The 305 uses a later, smaller bolt pattern than the 327. You'll need heads specifically designed for the 327's larger bolt pattern. Trying to force them on will damage the engine block.