cast crank 440, how much can it take????

550 FWHP should'nt be a problem, That'll get you around 470 or there abouts to the rear wheels, easy 10s in a 32-3300 A body with the right components/suspention, I know a few that pulled there cast crank 440s in the 65-6700 range with no issues bracket racing, GOOD machine work & lower end prep is key, but thats with any build. Plan on a total rebuild & change the pistons/rods, you'll need to get the compression up & a good set of heads, Now my old duster ran 10.75 & 125 with mild 906s at 3300+ lbs. race weight with the current owner, he weighs 300 lbs., Thats with a lowdeck 451, compression was 9.73 & a .590 MP cam. So done right & say a set of Indy EZ heads, .600 lift cam, about 10.6-10.8 comp, the right stall & gears with the race weight around 3200 lbs., No reason you shouldn't be able to run low-mid 10s..

I'll add, I ran a steel crank & factory 40 yr. old rods in that 451, Good rod bolts are "key", I was going to get the standard ARPs, but my machinest suggested the ARP "wavelock" instead, There a good 3 times as strong as a factory bolt, It had ross pistons, I trapped that engine at 62-6300 & a good 250 passes without a problem, The currect owner installed a .590 cam & 456 gears & twisted it to 67-6800 & trapped at 7200 & still no issues, Thats why the rods bolts are key, the rings finally gave up in 3 cylinders, rods/bolts never failed.