Need more speed

[rick1964]

Hi I'm somewhat new to boating, i bought from a buddy a 1970 18' schuster tahiti torino, it seats 6 to 8. The hardin marine 454 had to be rebuilt as well as the froze up berkeley 12je pump. My problem is that I can only get 54 mph gps out of the thing.... I think the motor has a mild cam in it. I'm not sure if the impeller is matched to the engine, my tac as well as my ear says the engine is only turning around 3000 to 3500 full throttle with a new holley 870 on it. Cant get anymore out of it. The engine has 8 hours on it so far... I had the heads ported and polished and have a mild high rise intake... Seems to me that motor should be pushing a little harder than that.... then again maybe not...... I'm thinking at that rpm the engine isn't reaching its power band...?