I have a shop manual for 85 to 87 gl, those have many vacume operations, many selinoids, many plug ins. I don't want to spenp $300 on little components to make a emission carb work, I had a Hitachi too.I New off the get go it would be problems, when I bought the car, disassembled, the guy said the carburetor had less than 6 hours use, however most of the components were gonw. My point is, the engine could not be tuned because of things being unhooked, plugged and obvisly not running the way it all was designed to do. I can take some pictures of the manuel to show the components that are required to make the Hitachi carb runable, however they are spendy as you know, yet will never be what you want. A few have told me that the secondary never had worked, most are running around with a one barrel carb. Let me know, I have been dealing with carbs for a minute, right now I have a 2 barrel Rochester on, it was bad at first, after making timing ajustments, a spacer, it seems great.I have a couple carbs, only into each $60 ready to go, if I get in gear and reassemble them, lol, willing to help out.