The unfortunate thing about an 86 is they are the only year that had the E6SE heads, which were the same heads that came on Crown Vics. This meant they also used different pistons. So aftermarket heads are kind of an "iffy" deal. However, there are several people who have used production (meaning off a Cobra or 5.0 Explorer) GT40 or GT40P heads in unison with the factory cam. In other words, I don't suggest doing heads and a cam, just heads. Don't bother with the E7TE heads, they will be a waste of time. I have the P heads, and love them. I got them for about $200 off a 67,000 mile Explorer. If you get higher mileage heads, I would change the valve springs.