back when they first came out i had a speed shop that i sold a few..everyone that got one from me loved them..they also worked real good in the 4x4's..at the time they came out you couldn't beat them for reponse and performance then.they was varable venture so they adjucted there self to size carb you needed.one size for all..the first ones didn't have a idle system in them but the next year they came out with the second model that had a idle system in it...they where the best in there time..the 3 major drawbacks they had that stop them was they munted where the linkage was in front of engine[instead of on side]so you had to build or buy a bellcrank linkage to use them..another drawback was no air cleaners fit them then.and 3rd drawback was the cost was double the cost of any other carb..i say that i sold a dozen or so of them before they phazed out.