UPDATE...
... (I know yer' all riveted)...
It worked... 158gph was weak, so I plugged 75% of the holes to get a good fill and flow to the front... (the 620gph probably would have done better, but might have been too big to submerge)... Ran the pump for about 2 hrs, then pulled the plugs and ran for 1 hr more...
Door closed, and window open... (I stayed out most of the time)...
Thanks for all the advice...
...