Engine RPM (and engine noise) in top gear will be exactly the same for a 4 speed manual as for a 3 speed manual, since both have a direct (1:1) output. A 3 speed automatic (C4, C6, FMX) also has a 1:1 top gear, but because the torque converter never locks up completely, engine RPMs will be somewhat higher at a given speed than with a manual. The transmissions themselves, whether automatic or manual, should be essentially silent. Noise (other than perhaps a slight whine under acceleration) is an indication of a dry bearing, a worn gear or some other non-normal condition.
With a small block engine, the wide ratio toploader is actually preferable as a performance gearbox in most situations, as the extra torque multiplication helps noticeably with acceleration. The main exception is road racing, where its desirable to keep the engine RPMs in a high and relatively narrow band, and running steeper rear gearing than what would be acceptable in a street car is the norm.
Close ratio gearboxes also make sense behind torquey big block engines, since they don't need the extra gear multiplication. But the "big-input" toploaders used behind 427s, 428s and 429s were all close-ratio from the factory, so it doesn't sound like you're dealing with one of those.