I've run exhaust above the skid plate with a PTO in 68 FJ40. Wasn't stock and a tight fit. Bought the stock exhaust for it from Toyota in the early nineties. It ran below the skid plate. Took it off after denting the front edge but still have in my pile of exhaust parts. Have 76 FJ40 with only 4,500 miles on it and still has the stock exhaust. Runs under skid plate and not that tight against it. Never seen a stock exhaust on 45 but can't see it being any different than a 40. It's awful for off-road but that's how they came. If you used it. Off-road at all it would get dented. Think around 72 a heat shield was added to the muffler. Once the exhaust changed in 75 a number of heat shields were added. But none were added above the skid plate. Would think if the exhaust was run above the skid plate there would be a heat shield there as well. I agree it was a stupid way to run which why so many can't except it was how Toyota did it.