You'll need the K24 head gasket because the bore is 1mm larger. Not sure on the gasket thickness, but check this out on JHPUSA. Look up "C4311-051"Hi, I am putting together a frank with a K24a2 block and k20z3 head. I’ve seen a lot of discussion about head gaskets but have not been able to figure out exactly which one I need. Can anyone tell me which I should use? A link or part number would be great. I know I need the gasket to match the K24 but i also heard that I need a coolant diverter...any advice is greatly appreciated!
https://www.google.com/search?client=safari&rls=en&biw=1440&bih=994&tbm=isch&sa=1&ei=Tp2jXLqAJo6e_Qbg8KnYAg&q=site:8thcivic.com+K24/K20+Frankenstien+swap&oq=site:8thcivic.com+K24/K20+Frankenstien+swap&gs_l=img.3...359314.359314..360549...0.0..0.54.54.1......1....2j1..gws-wiz-img.oymOl2x_GsE#imgrc=QqcG4ig5T1IiLM:Anyone know where we can get the pictures from this?