[Alan Roehrich]

Since most 393 Fords are based on regular Windsor blocks (maximum bore is usually 4.040", maybe 4.060"), and you have a piston made for a 4.155" bore, I'd guess what you have is made for an aftermarket block. With a 1.00" compression height, I'd have to guess the intended stroke is close to 4.00, because the aftermarket blocks are either 9.2" or 9.5" deck height. Without seeing the top, I can't hazard a guess as to what the head is that it is designed for. I take it there is no brand name or logo on them, nor a forging number?