Ok lets try these ones ,every hand helps,disconect EVERY vacume line and plug including brake booster if you have one(will some times suck air thru if faulty)get a can of engine start and spray around the base of carb,if no result spray on each manifold to head runner,if there are any leaks you will notice a rise in revs,also you can screw the idle needles all the way in on your carb and see if it still idles and check carb float levels,hope this helps.