I have a Miller Welder that has a Kohler engine on it. We had to rebuild the engine. Now the problem I am finding now is that the original Push Rods have a hole through them that the oil went through and the new ones do not. This is causing the top of the engine not getting any oil, or the engine to not have enough oil pressure to work. Is there any way to find the original push rods or is there something to do to stop this issue?