Ikf red plate vs WKA blue jr 2 flathead

[Birdcage]

What is the difference in flat head rules between WKA and IKF ? Which one of these engines would have the advantage WKA blue ,ikf red or wka animal blue all jr 2 engines and why ??

 

[one fat kart]

On the flat head the pop up on the piston is different,the IKF is 15 thous. and in the wka I think they are 10 thous. But in the wka you can mill down the surface more on the wka than the Ikf engine. They both run pretty close. On the animal I dont think their is any differance in the engines them selves. Who has the bigger hole in the plate. They are both flat plates now.