I am running a Pinto with a FR32 cam. The engine has done approx 7000 miles since rebuild (I did not do this myself so are unsure what items were recondishioned)

When you accelerate hard it drives like a dream, however when you lift your foot slightly off the accelerator you can hear a rattley noise. This can happen at any engine revs.

I have checked valve clearances.

My thoughts are that the cam followers could be worn (battered to death by a high lift cam).

Your thoughts would be most appreciated

Could be little ends, piston slap, or just tappets/followers. Also I have seen the centre cam bearing lug on the head casting part company on more than one ocassion but it's not likely to be that IMHO

Unreliable car engine you see - should have fitted a bike engine!!