I have done it on a 340,,its not to bad ,,but to get the pan off you have to remove headers in my case or at least take them loose,,and its easier if you remove tie rod ends that go thru the center link and idler arm an swing the center link out of the way,,then after the pan is off you can remove the rear main,,I used a punch to get the upper seal to start moving then it turned right out,,oil the new one good and get it started and it will roll most of the way in,,I did have to tap the end alittle to get it all the way around,,just be careful,if it seams to bind when going thru stop an back it out an oil better,,once in just seal the ends good as stated before and torque the rear cap back on,,I didnt have to loosen any others but that could make it an easier job