I think this might be a tough question for this forum but here goes. I was stealing some parts from some quadrajets I bought at the swap meet to rebuild the one on my truck. One of the carbs is from 1976 or 77 and it has an extra jet and needle behind the primary jets and needles. It also has a jet and needle that can be adjusted from the outside and on the car with a screwdriver. It is on the "bowl" opposite the accellorator pump bowl. In the other quads there is nothing in that space. Is this a high performance quadrajet? What do the other jets do? This one has 6 total including the 2 main and the 2 secondary. It was used on either an Olds or a Chevy with manual trans.