It does make you wonder if anyone actually designs the engine bays on RVs. It took me an hour to find I could fit a short spark plug socket that has 6 flats on the top so you can use a box end wrench to turn it. That eliminates the socket wrench handle and 1/2" of space required. That just fits between the engine and engine bay although you only have vertical space to go 1/6 of a turn before re-positioning it each time. Then when fully unscrewed you find there isn't enough room to take the plug out with the socket attached. So you have to screw the old plug back in enough to remove the socket. I could only get two fingers on the plug at a 90* angle to the hole. Getting the threads started with 2 fingers requires the patience of Job. So it is still a 3 hour job with a lot of cursing involved.You mentioned you replaced the spark plugs in your 87 460 Class C. Wasn't that fun. I tried on my old 87 460 class C and after 5 hours still could not get 1 hard to reach plug changed. I now have learned you have to jack up one side of the motor to get that plug changed.