You may want to rethink that, hitting 55 for a moment and sustaining it are two totally different things! The gearing required to sustain 55 is 10/30 or less so as not to grenade the engine trying to spin over 11k rpm, then that load and drag co efficiency come into play making it harder to reach the required rpm.
To sustain 55 for any length of time you ideally do not want to be wot the whole time ether which means you need to build the engine to be capable of higher speeds than that of which you wish to sustain, locking up an engine at 55 isn't much fun and depending on your cg (seating position) can be a painful experience!
BBR uses scraped castings, non branded engines that require a lot of work to make actual power and reliability from, many builders are lucky to even hit 55 as a peak with fully modified engines!