i went with the 1406 for a couple reasons. they are easy to tune. they are plentiful at good prices. I know them well and are super easy to set up and are mechanical secondaries. I like holleys but I have enough fun trying to get just one dialed in lol. I think a 500 would work just as well but these are what I had laying around. this is my first go around with a tunnel ram and I have had no issues what so ever, not even one single fuel leak. I set the carbs up exactly the same including the mixture screws all 1 turn out and I haven't had to touch it minus the idle setting.
