info please on builds

Hi .. I am planing on building some 1/32nd cars and I purchased all the size tubing you show in the builds like the MT 68 nova and the late model mustang how ever I have look over the way you build the chassis but it never says what size tube is use where on the build . Can anyone tell me which size goes where . Like what size is the main rail on the pm motor bracket Thanks for any help you can give
slotguy
slotguy