The problem with a Full on Boost/Nitrous 283 or 327 S/J Build is . No one make's 4-Bolt Caps For them and if they Did the Blocks are not thick enough to install them . As you Said install a Top Line Rotating Assemble . Yes that can and Needs to be Done . Because the Stock Rods are not very strong with there 11/32" Rod Bolts . You can Buy some Pro Rods with Cap Screws . And Stud the Main Caps this will make the short Block Stronger . But If some one had there Mind Set on Building a Stronger 283 . Take a 307 Block and install an L/G 3.000" Crank . Now on this Block you can add the Splayed Main Caps . And Use the Stronger L/J 5.7 Forged Rods . Then you would have a Stronger 283 to rage on .