Info on the tube measurements on the SA-5
BT-70 Length in inches 3 5/32" or 3.15"
BT-19 Length in inches 7 29/32" or 7.91"
BT-50 Length in inches 10 3/64" or 10.06"
BT-58 Length in inches 1 47/64" or 1.73"
Center of Gravity balancing point is 11 7/32" or 11.22"

Info on the tube measurements on the SA-7
BT-70 Length in inches 3 5/32" or 3.15"
BT-19 Length in inches 7 29/32" or 7.91"
BT-50 Length in inches 10 3/64" or 10.06"
BT-58 Length in inches 3 9/16" or 3.56"
Center of Gravity balancing point is 15 35/64" or 15.55"

Have read the instruction. They are pretty easy to understand.
Well the first thing for me is to cut the BT-19 tubes and layout the weld lines
and position the UNITED STATES on the tanks.