I some what agree with Woodswarrior there. The 454 is easier to make power cheaper because there is a bigger aftermarket for 454. But a well built relatively stock 455 will produce more torque than a compared 454.
Problems come because of BOP bellhousing. auto vrs 4 speed manual. Pilot bushings and crank mods can be tricky for 4 speed conversion.
It may not be easy but its not hard either. Just takes time and searching and making sure you get the right parts for the swap.
