The Ford 400 engine was based on the 351 Cleveland. It had a half-inch (12.7 mm) longer stroke than the 351 Cleveland, making it the longest-stroke Ford pushrod V8 engine. The 400 had "square" proportions, with a 4.0 in (102 mm) bore and stroke. Ford called the engine 400 cu in but it actually displaced 402 cu in (6.6 L). To accommodate the longer stroke, Ford engineers increase the block deck height to 10.297 inches compared to the 351C's 9.206 inches. As a result, the 400 used longer (6.580 inch) connecting rods than the 351C (5.778 inch), but it retained the same connecting rod-to-stroke (1.65:1) ratio as the 351C. The 400 featured larger 3.00 inch main-bearing journals, the same size as those used in the 351 Windsor, but rod journals were the same size as the 351C. The cylinder heads for the 400 were the same as those used on the 351C-2V, having the open combustion chamber with smaller 2V sized ports and valves. All 400s were low performance engines that ran on regular fuel and all used a 2-barrel carburetor, a cast-iron intake manifold, and small port 2V cylinder heads.