First, I already had an edelbrock 2104 manifold with my Q-jet on top, so that was already done. My problems with the Qjet- no choke, sometimes it could be hard to start. The fastest I could go without getting into the secondaries was 3500 rpm after that fuel economy went from the low 2s (mpg) to the mid 1s. If the boat was heavy (6 plus pass.) it would bog in the secondaries- I dont think I got enough rpm in the primaries for the secondaries to work well.
Ill admit I cheated and test ran a 1405 on this motor a while back- I knew what I was in for, the 1409 runs all the way to 4000 rpm in the primaries, economy might be slightly better at best cruise (3200rpm) time will tell if this is true, but I can run all the way to 4000 and still have the economy over 2mpg. Top speed is overall about the same 4800 rpm (41mph) and 22.5 gph with the Qjet and about 4700 (40) and 20.7 gph with the Ebrock. All in all I'm pleased with with the difference, couldnt get enough people to weigh the boat down in 30* weather, but I think it'll be better than the Q jet with a heavy load
Ill admit I cheated and test ran a 1405 on this motor a while back- I knew what I was in for, the 1409 runs all the way to 4000 rpm in the primaries, economy might be slightly better at best cruise (3200rpm) time will tell if this is true, but I can run all the way to 4000 and still have the economy over 2mpg. Top speed is overall about the same 4800 rpm (41mph) and 22.5 gph with the Qjet and about 4700 (40) and 20.7 gph with the Ebrock. All in all I'm pleased with with the difference, couldnt get enough people to weigh the boat down in 30* weather, but I think it'll be better than the Q jet with a heavy load