Hi Max and Jeff, The motor I just pulled the big boss off had the offset manifold. All the mowers with the gray curved tops have the straight manifold, you can't fit the standard plastics with the straight manifold because the fuel tank hits the carby. This is the first big boss I have come across and I have no idea what mower it came off. I am picking up the 600 in the morning so I should have an answer tomorrow afternoon. Jeff, there is not much room above the pulley was thinking maybe a 1/2 inch thick piece of plate to make a disc out of. Will see how tomorrow goes
