I'll knock your block/head off!

knock (one's) block off

To strike someone with great force, usually in the head. If you insult me like that again, I'll knock your block off!
See also: block, knock, off

knock (one's) head off

To strike one with great force, usually in the head. Usually used as a threat or a hypothetical action. If you insult me like that again, I'll knock your head off! That football nearly knocked my head off. I'm glad I ducked in time!
See also: head, knock, off
Farlex Dictionary of Idioms.

I’ll knock your ˈblock/ˈhead off!

(British English, spoken) used to threaten somebody that you will hit them
See also: block, head, knock
Farlex Partner Idioms Dictionary
See also:
  • knock (one's) block off
  • knock block off
  • knock someone's block off
  • block
  • knock someone’s block off
  • cut off at the pass, to
  • the block is hot
  • What will that prove?
  • go on the block
  • block off