Alright guys, big update. After I woke up from Thanksgiving (aka "food coma"), I got pretty busy with work, but I did have some time to do some detective work.
Samiam44, I found the same article you quoted from, on
http://www.kohler-engine-parts.opeen...ts/piston-kits. According to the piston design, the kit I have (which I'm pretty sure was manufactured by Stens) includes the old style piston. I have had Kohler places ask me if I'm using the old style piston, and this is the connecting rod they've come back with. But the connecting rod and piston seem to work well together. It's the piston vs the block that is the problem.
So I took some pictures, and I took some measurements for y'all to see. A picture is worth a thousand words, and I tend to be rather wordy, so maybe this will shut me up!
First picture is of the difference in size. I put the old rod on the left, new rod on the right, and measured the width of the rod in the area where it was hitting using calipers available at work. I measured the new rod at 0.200" wider than the old in this area.
https://lh5.googleusercontent.com/-P...20modified.JPG
The second picture is a zoomed in view of where the rod was hitting the bottom of the cylinder wall. There was a bit of flashing left from when it was cast, and you can see two lines; one where it hit the cylinder wall when I turned the engine it's proper rotation, and the other where I turned it backwards to see if it would hit that way too.
https://lh3.googleusercontent.com/-5...0/100_1590.JPG
At the suggestion of the last Kohler dealership I talked to, they recommended polishing this area down to remove that excess material, and see if it will fit then. I have polished it down very carefully, making sure not to take off much material, or let the rod get too hot in the process. Here's the finished product.
https://lh3.googleusercontent.com/-M...0/100_1591.JPG
I'm pretty excited to put this thing back in and see if I have enough clearance, but it'll be a week or two before I get the chance to do so. It doesn't seem like it'll take much to clearance the rod, so I'm hoping what little I did will make the engine and its owner happy.
I apologize if I am not posting my pictures correctly. I know some forums get pretty upset about this. If I am doing it incorrectly, please let me know and I'll e happy to fix. I haven't yet found the rules for posting links to pictures hosted elsewhere.
Thanks for all your help, and I'll keep you updated.