SORRY I MUST OF SCREWED UP SOMEWHERE AND POSTED WRONGLY....
A STANDARD DECK HEIGHT OF BBC IS 9.800 INCHES.TAKE HALF OF THE STROKE U GONNA USE(2" FOR A STANDARD 4"STROKE OF A 454)AND ADD A PISTONS PIN HEIGHT(CENTERLINE OF THE WRIST PIN TO THE PISTON FACE) AND SUBTRACT THE DECK HEIGHT(9.800")THIS BECOMES YOUR REMAINDER.THE REMAINDER IS MAXIMUM ROD LENGTH U CAN USE....GOOD LUCK