I have to agree with ya, lofly'a, on the second job being "easier" for the novice - in some respects. But... hear me out.
I have a good friend that owns a machine shop and I approached him about doing a notch job on my spare crossmember. We looked at both ways of approaching the "problem". We looked at the one installed under my truck and talked about it. We both decided that, all things considered, cutting all the way across (i.e., the first approach) would be the way to go.
Here's "why."
First off, a plasma cutter isn't required (although it would be nice). A Sawzall with a good high quality metal cutting blade will suffice for the large part of the cutting. Getting the Sawzall into the corner for the cut across can be accomplished by drilling a hole at the corner into the portion that will be removed.
Second, there wouldn't be any clearance problems with the oil pan or tie rod - therefore no notches. The engine mounts wouldn't have to be cut because the dimensional relationship between the frame and their mounting surface of the crossmember would be the same.
No offense, just my "two cents worth".
--
woohoo, 100 posts.