I have a Edelbrock Vortec TPI baseplate and and getting ready to install it. The intake came with a small plate to block off the hole where you would install the external Corvette EGR tube near the rear passenger side. What do you use to block off the hole right in the middle of the intake where the stock EGR valve sits? Do I need to put anything there or because the heads have no EGR passages it is OK to leave uncapped?

You have to seal off where the EGR valve fits because one side goes into the intake (vac ).
Once that is sealed off ,then the rear Vette fitting is only sealed for cosmetic purposes .

A TPI EGR block off plate
Given you can't actually see it, a bit of steel plate the same shape with 2 holes and a gasket works just as good

http://www.ebay.com/itm/Drag-Racing-Camaro-Corvette-TPI-Eliminates-EGR-Billet-Aluminum-Block-Off-Plate-/261245587221?pt=Motors_Car_Truck_Parts_Accessories&hash=item3cd3734f15&vxp=mtr

Thanks, I figured as much. I can make a block off plate out of some steel and will use the supplied block off for the rear holes.