Installing quarter panels: how level does the floor have to be?
 

I'm in the process of installing new quarter panels, inner deep tubs, outer tubs and trunk dropoffs. As I understand it, the car should be sitting on the wheels to get the best fitment, or have the car on jackstands where the wheels would be. Does this sound right?

Also, I was told to make sure that the floor is level. How level does it have to be?? I put one jackstand on one side of the car and one on the other side of the car making sure they were both the same height off the ground. I then put a long level on the tubing to see how level it was. The bubble is between the two lines, but closer to the right line. I lifted the level up slightly (less than 1/3") and the bubble centred. Is this level enough or should I put something under the jackstand to get the bubble right in the middle?

Thanks in advance.

The floor has to be perfectly level if not build you a frame jig or table thats level and put the car on it.Are you sure your level is level they can get out of level.Easy way to test a level is put it on something then turn it around if the bubble goes to the same spot both times then its fine.

To be perfectly honest it isn't so much that the car sits on a perfectly horizontal level, moreso that the car sits with the weight on the wheels/tires or with jackstands under the axle/front A arms, supporting the weight of the car as if it were sitting on its wheels. All of the alignment starts with getting the gap to the doors correct, with of course, the front fender to door gap being correct as well. Get everything fitting correctly & clamped up before you weld anything & then tack it all together first before final welding, constantly checking that evertything lines up correctly & hasn't moved dure to heat build up. Hth.

That's good to know, thanks for the help. I just checked my car. It's perfectly level front to back. Side to side...it's close. The bubble is between the lines, but touching one of them. That was with a level across the top of the trunk opening. Even when I lay it across the top flat part in the trunk...it's still about the same. I already have the passenger side quarter off so would that effect it some I assume.

The fact that the 1/4 panel's off shouldn't make a great deal of difference. Over the years I've seen people remove 1/4 panels with just the rear end up on jackstands (I've been in the body shop game for over 30 years). The important thing is to have the car with it's weight supported by the wheels or on jackstands under the axle/front suspension when aligning everything & whilst welding takes place as this is how the car would "sit" when back on the ground. If you're really worried just take some measurements across the aperture from side to side but I bet they're almost the same (remember that even new cars can be out a fraction dimensionally & an old car even moreso even if they haven't had bodywork, due to the torsional/lateral stresses imposed due to everyday/hard driving use). hth.

Thanks for your help. The car right now is sitting with the jackstands under the rear housing and under the control arms. This will certainly make the job a lot less stressful trying to make sure it's perfectly level in every which way.