a 413 crank will fit a 426 hemi ,and fit a iron TF,,but i question the iron TF handling that much power,,.id use a 62 to 64 727 cable TF ,,.late TF parts will fit from late 727s,,.also the 727 is much lighter than a iron TF ,,.a 392 is 200 to 300 lbs heaver than a 426 hemi,depending on equipment,,.look at the weight of a 360-727 and compair it to a 392 -iron TF,,over 500 lbs different ,and 300 hp is not hard to do in a 360,,.my 1 ton trucks all have 360s in them ,they all weigh over 5500 lbs,,and will keep up to my 59 and my 61 imperials with no problem,.about the same gas millage,.the trucks will cruse at 75 all day and seem to like it to,,.do some power to weight ratios,it gets very interesting and surprising too,,...rick