Break in problem
 

I recently rebuilt my 2.7l. Pretty much everything is new. I was trying to do the break in procedure as directed in Wayne's book. The engine started up just fine and I took the engine up to 2500 rpms and was planning on leaving it there for 20 minutes however after about 10 minutes I found that the 4,5,6 bank wasn't firing. I don't know how long it wasn't firing. May not have ever been firing. I tried a few things and couldn't get that side working so I shut down the engine after 10 minutes.

I believe I figured out the issue and now I am ready to go at it again. Do I just start the break in procedure as though I hadn't done anything before or do I only do it for 10 minutes...?

First thought is the right cam is 180 degrees out.
You can verify this by going to #4 TDC, pull the distributor and swing the rotor to Z1, install.
Now starting up, you will run on 4.5,and6. If it happens, you installed cams wrong
Bruce

I believe my issue was a carb related issue. The 4,5,6 bank carb was overflowing.

If I was 180 off on the cam- wouldn't I have a valve striking issue? When I originally installed my cams, I was 180 off and I couldn't turn the engine cause the piston would hit the valve. I corrected it and it seems fine now. Is it still possible I could be 180 off?

My main concern is how to go about doing a break in redo. Just start over or start where I left off?

The purpose of 20 minutes at 2000 is to run in new cams. I assume you are using new or reground cams? If so another 10 minutes, should suffice.