On a 104 HFM/SFI , if you DON'T feel the Runners change length and the cam advance , THEN there is something WRONG..this is a Performance power-plant, and when Engine Management calls for the power/load intake runner matching and cam valve advance mapping , it is a noticable change ...don't compare the power/torque range habits of a 104 to a 103 .... 104 HFM/SFI is a full electronic, distributorless, high performance engine and has nothing in common with a 103 engine.
They are light years apart.