I had the same question some time ago. I had my question answered by Duane at Hi-Tech. The 174 will work on a 454 and give quite a bit of extra power, but the 250 B&M will do it by spinning the blower a lot slower, and not heating the air as much. That's important on a covered engine boat like mine on a hot day. I had them install the 250 B&M and just love it. Went from 63 to 81 mph in my SS Taylor. I also used the carb, cam, and fuel pump that they recommended.