What is the exact reason for having to drop the exhaust to change the oil? Is it the plug or the filter that it blocks? can it be done but just hard or is it totally impossible?
Most of the time you have to remove the exhaust headers, because otherwise the oil filter itself doesn't have enough clearance to get around the pipes or in between them. Taking the exhaust off also makes it easier to get at the nuts holding the oil filter cover in place.
When I take my oil plug out, sometimes the oil drips onto the pipe after it starts to trickle. the header bolts need to be removed to get the filter out as stated above.
My Previous Owern put a D&D on, and I have to remove the exhaust to even get the drain plug all the way out. Forget trying to get the filter out without taking the exhaust off.