Stop in for a cup of coffee

Never done them but if you don't lift the car on a unibody correct yea that would cause some problems on fitting. Not saying your doing it wrong so please don't take me wrong but before you weld it all in make sure doors and fenders are inline. Just my 2 cent Buddy.
I am doing it on the ground, i got the passenger fitted and am waiting on paint to dry inside of it then will weld it in in the next few days.. Took bout 2 hours or so of grinding to get it fit but it came out decent. And hell my doors didn't fit for **** to start with :) Hinge rebuild is on the list..

P.S. the 2hours was mostly... get under the car, lift the part into place, jack it into place.. mark the spots that are too high.. reverse process.. grind.. try again.. abut 20 times:)