Cut Out Full Length Floor Pans Twist Warp

Got the front of my 68 coupe on jack stands the rear on it's wheels.  A slight angle but not level for sure.  I am about to cut out one full length floor pan at a time (passenger side first then when done do the same on the driver side) and weld in a new one.

The question is will cutting out a floor section that big weaken the structure to where it can twist or warp the vehicle? Am I better off making the car level, only lazyness prevents me from doing so, LOL.  Is any temporary bracing required?

Apologies for yet another floor repair thread, but I like to ask specific questions, they may help others out as well in the future and may be easier to search / find.

Thanks in advance,
California Greg  

hi greg...  i ask another forum member to drop in.. give you some advice..

you might want to invest in a laser leveling device.. one that sends out a crossbeam..  so you can get the car dead level on the stands..

you can use thin plywood squares to raise the jack stand bases to bring the car level..

i have always wanted to drill the sides of my click type jack stands to allow me to put two bolts through to install a pinch plate..  this would allow me to grab the pinch weld firmly..

the laser can be used with dangling pieces of masking tape.. carefully marked to establish where the car is square.. without needing to climb under and measure each corner of the center..

do you also have a frame dimension chart???  

Hi Gregski and Wayne- I haven't done a Mustang floor replacement, but ...

Heres a link to a helpful article with good pics at a sister magazine site:

http://www.mustangandfords.com/techarticles/body/mufp_0805_vintage_mustang_dynacorn_floor_install/index.html

As shown in that article and many others around the web, you just need to support the car near the torque box areas and use common sense in supporting other structural areas to hold them in place while you do the deed. Undamaged hardtop cars (no B post and not convertible) can generally be trusted to not distort with the floor out, if the inner and outer rockers are solid and securely supported with stands. Being exactly level front to rear isn't critical but you don't want one side higher than the other. A selection of wood blocks can come in handy.

I would have more specific input if I saw the old and new floor, but I think you'll get the idea. The answer to the bold question is no, in my opinion. Just use caution and proceed with your plan!  

you gotta know when to fold 'em

well after practicing MIG welding some sheet metal and failing big time, I decided it is best for the pros to handle this task, so I had the car towed ($65 bucks) on a flat bed truck to a local shop that specializes in classic mustangs, I really wanted a car guy to weld in the new floors and not just a good welder, know what I mean

let me tell you how the costs break down before I give you the bottom line, as they did more than just the floors

first of all this does not include the sheet metal, I bought the sheet metal on my own from a local mustang store and this shop was totally cool with that

so to weld in two full length floor pans (driver side and passenger side) plus two seat risers (you guessed it driver side and passenger side) it was $650 bucks, not bad

this included sealing the seams and painting the work inside the car and underneath the vehicle with POR15 plus coating it with this undercoating spray (I forgot the name so I will take a picture of the empty spray can they gave me to do the rest of the inside with)

take a look at the pictures I think it turned out great





 

You got a lot of labor for your money Greg! good post.  

Luv your Grand Prix old/new photo. I just love the 1969-71 SJ's. Big and bling.