The 84/85 and 86/87 IAC are different but only the tip, I work at Oreilly Auto and I ordered in a hot air IAC just to check them out side by side we have the 86/87 in stock, the tips were different and the price about 50 bucks more for the hot air IAC, I'd sure like to know if the 86/87 would work in the 84/85