It's taken years to get the hang of this and I'll try to pass it on. Recently I have built bins for modified engines using fuel pressure and bin settings then used stock VE tables smoothed and came out so close no VE tuning was needed! It's something I do to all bins I tune and it makes it easier tune.

Read this for a starter.
http://www.gearhead-efi.com/Fuel-Inj...ll=1#post12348

The Tables you have are a guideline. All four corners are the guideline, they can change. Save your bin and make another to work on and use the old for Compare. Who knows what software GM used back then but the procedure was to dyno engines to MBT which is pressure at 15 degrees after TDC, then had to pass driveabilty and emissions and still have drive ability. It's obvious some areas were just grabbed to meet the needs! It passed so they were done. Or in some case never even worked on, like your main VE table, look at 20 MAP column, it is going up then stops and goes down. Not likely to ever see that area.

So your VE table fix the 20 MAP and where it goes to 59. use that number for rest of column. Or you could leave it alone. Rest of it looks OK, so I'll give a simpler approach. Click 100 MAP and all cells will highlight. Use Smooth tool and set to .7 and execute. Then do all the MAP columns, then do all the RPM columns. Now compare to starting bin and Compare, use the difference Icon and you'll see not many drastic changes between the 2 except the 20 MAP which we changed. Look at table in Wire frame View. Which do you think will work better?