There are four basic FE crankshaft sizes—3.30-, 3.50-, 3.78-, and 3.98-inch strokes. There are two basic FT crankshaft sizes—3.50- and 3.78-inch strokes. You can opt for a short-stroke steel crank for your 352 or 360 mill by going to the FT (330 and 359ci HD engines) parts bin for a crankshaft. You can also use a longer stroke steel crank from the 391 FT in your 390 or 406. However, the FT crank calls for special modifications that can be performed only by a machine shop.