Ayuh,...... I had a '74 221 S/C Islander, 'n pulled the 120 hp/MC-1 , 'n dropped in a '94 4.3LX/ Alpha 1, then ran it for over 20 years,.....
With the 4 banger it did 'bout 28 mph, but never 30 mph,......
With the 4.3LX it pulled a consistent 43 mph, with of course, neck breakin'...