We are working on a 75 T140V. The problem we're having is, after assembling the engine the intake valves are coming in contact with the pistons after the timing marks are aligned.One of the manuals, (Haynes) we're using lists two different lengths of push rods, (one being 4+mm longer than the other). Does anyone know if the intake pushrods are shorter? The valve settings are a bit out of the ordinary, with .008 intake, and .006 exhaust. The intake valves are noticeably larger, too.