Much easier to modify without the engine in there. Another route to go, and more complex than the standard chop, bend and add a spacer approach is to make a removable cross member. This enables you to drop the oil pan without having to pull the motor. If you’re interested in that approach you can see how mine is setup in the Dirty Koala build thread in my signature.
I'll definitely have to check that out! I like the idea of a removable crossmember. I've been slowly going thru your thread during my build, and have been grateful for a lot of the info there. its helped me out quite a bit. a big thing I noticed is we have the same transmission, and everyone else seems to have the newer style with the two piece shifter. I thought for quite a while (until I saw your thread) that I was going to have to change that.