Fly by Nite 4 #1 Posted March 8 Can anyone help me? I have two wrist pins, one with a thick wall " heavy" and one with a thin wall both fit but which one is the right one for a K series 321 engine ?? Share this post Link to post Share on other sites
squonk 38,967 #2 Posted March 8 (edited) Pins are fitted individually to a piston and are balanced as an assembly. I have a collection of broken rod piston assemblies on a shelf. 2 12 HP pistons and 2 16 HP ones. Each size has a thin wall and a thick wall. So there is no way to tell what wrist pin is the correct one for the piston you are using. Either one will probably work but it may be unbalanced some. Edited March 8 by squonk Share this post Link to post Share on other sites