suspension parameters and settings

[69charged]

hello all. i was wondering how a person goes about doing the front and rear suspensions when using kits? what i mean is i am building new rear frame rails with an a.m. 4bar in the rear and converting to coil overs in the front on my 69 charger. as i build it, how do i know where to set ride height when there will be no engine, interior and such. i plan on assemling pretty much everything then ripping it down again to paint but how do i set it all with no weight?
any recommendations would be great!! please!!!!
clarence