Crossmember swap help

[et cetera]

So, I've been trying to swap a 63 crossmember on to my 62 and I hit a bit of a problem and need some help.

I have been reading dozens of threads on the topic, including the most commonly referenced one, http://67-72chevytrucks.com/vboard/s...d.php?t=366850, and I still cant figure out if I'm lining things up correctly.

I wasnt able to take any wheel base measurements from the old crossmember, but I was hoping I could get 1-2 of the original holes to line up so to hold it in place. From there I was just going to drill out the holes where they sat.

Right now I have the center bolt in the inside of the frame aligned, it also looks like the forward most hole would also align there. You can see it in the first picture.

on the outside of the frame I was expecting another hole to be lined up from what I had read, but this doesnt appear to be the case. It actually looks like I could move the crossmember back a bit and the two top holes would line up.

This is the same on both sides, so everything seems to be straight.

My question is, which hole should I have lined up before I start my drilling?

Thanks for the help.