335 hp engines usually got the HP exhaust manifolds, while the 330 hp engines usually got logs like the 2bbls.
My '68 Superbee still has its "born with" 330 horse motor. Many '68 bees were actually 330 horse, by '69 the 335 was standard. This is verified on the trim tag as an engine code of 62 (330 HP) vice 63 (335HP).
My 330 horse has exact same 906 heads, exact same HP exhaust manifolds, and exact same unsilenced air-cleaner as 383 HP and 440 HP motors. It did not come with windage tray but did come with a 402 pan. Parts book says cam is 2531190 for 330 horse, 2843564 (440 HP) for 335 horse. Carbs are the same by application between the two 383 motors, distributors are different part numbers, likely different advance curves.
Bottom line, more cam, recurved distribuor, and windage tray were the only difference.
