Kohler 18 HP into a 20 HP??? same bore and stroke what do i need to do?

[Hogneck]

Hi guys! happy holidays. The kohler 18 HP and the 20 HP are the same bore and stroke (the 23 HP is a bigger bore... he he he) I think i may have a bead on a kohler that is in my price range. I looked up parts numbers and i cant find any discrepacies. So tell me, is it the carb? is it the exhaust? is it the timing? is is the cam? if i have to rebuild an 18 may as well make it a 20 right???? Thanks in advance and what are the part numbers?

What is the displacement for 23HP? 18hp is 570cc I believe.

[spookum]

Hi guys! happy holidays. The kohler 18 HP and the 20 HP are the same bore and stroke (the 23 HP is a bigger bore... he he he) I think i may have a bead on a kohler that is in my price range. I looked up parts numbers and i cant find any discrepacies. So tell me, is it the carb? is it the exhaust? is it the timing? is is the cam? if i have to rebuild an 18 may as well make it a 20 right???? Thanks in advance and what are the part numbers?