On the 700R4 not being able to shift into OD at wot.
 

There is a valve change so that it will shift into 4th at wot. I have heard that the clutches are small on OD in the 700R4 and if you put the valve in . These small clutches may be a problem. I get the impression that is the reason they designed it not to go into 4th at wot in the first place.

I would like to know what the results of people putting in this valve to go into OD at wot. Any experience with this out there.

A stock Corvette back in the day would stay in 4th at WOT at the factory.
When I ran my 88 Camaro Iroc-Z , we had added the valve and the tranny shop did some other upgrades,lHD servo,different springs,but it was still the stock clutch setup.

Mine you it wasn't the same engine horse power that we have now in the newer cars. But once the tranny guy did the upgrades,had no problem doing WOT in 4th gear with a mild built 5.7L.