In my mind, the best engine for 1953-56 F-100s is the biggest engine Ford had at that time, bored and stroked to the limit. The 1952-57 Lincoln Y-block 317-341-368 is that engine. The LYB has a 4.625 bore spacing, 10.94 block deck ht ( from crank center ), 5.152 cam to crank centers. The 368 has a 4.00 bore x 3.66 stroke, and can be bored to 4.125, and can take a 4.35 stroke with stock con rods. But I was thinking of a 4.375 bore x 4.50 stroke -541 CID custom cast, custom billet LYB. I dont have the $ to make it happen. 541 LYB specs : 1.50 piston pin ht, 0 deck clearance, 7.20 con rod length, 1.6 rod ratio, 10.95 block deck ht.