I found a rebuilt distributor in my parts stock.  It was supposed to be a 57 Ford Thunderbird tach drive distributor.  When I took it out of the box it looks similar but is much larger.  Similar to a Y-block distributor in steroids.  I thought it was for a big ford 332 Y-block in the heavy truck, but I heard they are the same size distributor as the smaller y-blocks.  Anyone have any idea of what it fits?