Of Oilpumps and its sizes (pump sizing and use)

good day all,

as noted on my previous thread, will be building/rebuilding two motors , a 1679cc and 1800cc ( 88x69 and 88x74 respectively)

recently acquired 2 AD stamped cases, dual relief, one is 10mm studded, which will be used on the 1679cc and the 8mm stud will be for the 88x74,

both cases are used/seasoned, checked out good on the tunnel bore (mains) will final check pre assembly though,

plugged and tapped for full flow (to be done soon)

the 1679cc will use a 26mm schadek pump, plugged for ff, and sanded for min. clearance by me

i was wondering though.. on the 1800

would a 30mm pump be useful than a 26mm? seeing that this will be used more often,
an external cooler will also be mounted at the front (added oil lines myt eat up psi)

the oil choices i have are, 5w30 and 10w40 (theyre the usual weight of the good brands available local)

temps here are bet. 29-34deg celcius , all thru out , being a tropical country,
but its darn too humid, it almost feels like its hotter than it is, if that wil play a factor in the oiling system and temps?

Jim "Sare" Edmiston can attest to the humidty here hehe

was wondering what you guys thought? im already leaning towards the 26mm pump ofcourse, but just incase i should do 30mm..

i thought of running the question with you lot,