I've been running about 60 taps into a 4008 I think it's rated at 3.0 gpm. I'm using 3/16 since the rest of my woods are pretty steep. I have 4 laterals on this pump, the longest 800' or so, the shortest a little over 200' with 17 taps and the pump actually pulls this sap up hill and manages 25in/HG or so. I had a few 3 gallon per tap days last season.
In years past, I had shurflo's on 3/4 mainline with 300 or so taps. I'm not sure of the CFM just overwhelmed the pump or the squirrels overwhelmed my tubing, but i could never get more than 10in/Hg pulling on 3/4". I like the newer shurflo 4 diaphragms a lot better than the older 3 diaphragm pumps made by both shurflo and ever flo, even though one or two everflo's I used were 4 gpm, they only had 3 diaphragms, and would not pull near the vac that the Shurflo 4008 pulls. I'm not sure if it's the extra diaphragm, but it definitely pulls higher Vac. I have not used recirculation, and with the wire mesh strainer, I can let the pump run past freezing, the screen catches the ice and the pump pumps itself dry so nothing to freeze and tear the membrane. Also if I don't make it out until after it thaws, the sap will run through this pump without it being turned on.
With 2 100 watt solar panels, I don't have to carry a battery out every other day, cost me $200 but saved my back.
Good luck!!
'12 15 jugs - Steam pans
'17 125 3/16 - 18" x 72" drop flue on homemade arch
'18 240 3/16 - Deer Run 125
'19 450 3/16 - Converted RO to electric/added a membrane
'20 600 3/16 - Maple Pro 2x6 Raised Flue, added AOF/AUF
'21 570 3/16 - Built steam hood, Smoky Lake filter press
'22 800 3/16 - Upgraded RO to 4 4x40
'23 500 3/16 - Re-plumbed RO, new "Guzzler"
'24 500 3/16 - Steam Away, DIY 8x40 RO