I currently own a john deere lt155 which hhas a 15 hp kohler engine. I am wondering if I can replace this engine with any similar kohler command engine? I'd appreciate any insite... thanks

Hi,
Bolt pattern and crankshaft dimensions are pretty much the same for any comparable engine. See:
Your online source for Replacement Small Engines. Vertical Shaft Engine Measurements. (http://www.smallenginesuppliers.com/shop/html/vertical_shaft_measurements.htm)
Peace,
Clarke