I have 4 Fox 25BB schnerl ported engines, numbered 1 thru 4. These came out of a Globemaster that never flew. Engines were custom ordered thru Fox and were matched run and checked out. I'm in the process of finding a home for the Globemaster, Air Force Museum, All are identical possibly a tank of fuel thru them, probably less. No Mufflers, no boxes and number 4 has a broken high speed needle. All very clean and turn over nice and great compression. Buy one or all four your choice, they are all numbered on both sides.