Question re: two turkeys on the WSM

I am going to be doing two 15-17lb turkeys on the WSM at 325-350. My plan right now is to use a foil pan for the bird on the bottom rack and put the top one on a wire rack holder, so its basically right on the grate. Couple of questions:

1) Will the pan on the bottom have any effect on the smoke / heat which reaches the top bird? Its an 18.5 WSM and the pan is like 15"+, so to some extent it will be extending over the edge of the water pan.

2) Any thought on cooking time for two birds of that size?

Thanks for any suggestions and hope everyone has a great and successful turkey day!

Well I am doing something pretty close myself. I have a 22"WSM and will be smoking (2) 14.5 LB birds in the morning. I did foil the pan as I do for chickens. I will smoke around 325 degrees to thigh temp on the bird (bottom rack) to 175 degrees. Both of the birds will be directly on the racks, so I am not sure about the pan having an affect on yours but I am betting no affect. I am assuming you will not be using water in your pan since the temps will be so high ? I am betting they will be done in about 4 - 4 1/2 hours. I will allow up to 6 hours and If I were you I would allow at least that. If you can get your heat to 350 you should have no problem meeting that. Good Luck

Yeah, no foil on the pan. Will do the standard method for the coals, so it should get pretty hot. Thx for the response!