call prosystems. best carb i ever had. gave them all my specs, carb was spot on out of the box. only change i had to make was to open up the idle air bleeds a few sizes. picked up 2/10ths. on cold start up, idles on it's own after 10secs. 440sb, street/strip, best et 9.61. 10.5 mpg. stay safe, seeya.