I have a 55 POntiac 287 engine that I rebuilt and decided to install in my 53 sedan. The problem is that I can't seem to get the correct flywheel to work with the stock 55 bell housing and starter. I've been told that Pontiacs form 55 to 60 use a 14 5/8 inch outside diameter flyheel (ring gear outside measurement) and 176 tooth ring gear but this seem too large for the 55 bell housing. The starter jams up in the flywheel and can't turn the engine over. I have tried modifying the starter by grinding off the rim  and elonging the lower mounting hole but it is not enough. I am of the thought that the 55 engine uses a small 14 1/8 inch flywheel? Oh, yes, I have 2 55 starters and 1 56 and they all do the same thing. I have also tried an aluminum Schiefer flywheel that is supposed to fit 55 to 60 with the same result.