Kohler 10hp and 14hp Cylinder Heads and Valves

[Polaris2007 4]

Guys, I have a 10hp Kohler that I am boring out to accept a K301 12hp piston. the block has "K301" cast into it on the PTO side, so there is plenty of "meat" to bore out for the K301 piston. I am getting a K301 crank from a fellow Redsquare member. My questions are about the cylinder head and valves. Are the 10hp valves the same as the 12hp valves? Can I use the cylinder head from the 10hp? I just bought a K321 14hp last night, and i noticed that the spark plug is located more toward the PTO side, like right over the exhaust valve, as opposed the my 10hp head, which has the spark plug more centrally located in the head. What is going on with that? Do you guys think i can use the 10hp head with the 12hp piston, or do I need to find another head? Thanks guys......

[TT-(Moderator) 1,147]

In this case, the valves and head are the same. (meaning - interchangeable)

The relocated spark plug was an attempt to get a more complete burn within the combustion chamber.

Some of the "pulling crowd" swears that it helps make more power, but not without other modifications.