ok. the 351M/400 has the most potential per cubic inch of any motor that ford built. thats why its won the jegs engine masters challenge the last two years in a row, and took second the year before. simply changin the timin gear to correct the 6 degrees of cam retard puts the 400 at very similar numbers as a stock 460. throw a good, say level 2 or 3 cam at it, four bbl carb and a set of headers and say hello to over 300 HP and 400 ft/lbs. add some good heads, a lumpier cam, and few compression points and your between 375 and 450, and 400 and 500 and still have a streetable motor.

TMeyer, Inc. Precision Automotive Machining

400 Ford: Peformance From Another Aftermarket

FordMuscle - SBF 454 Build - Circle Track Ford

the last two links are on tim meyers page.