My new floor pans should be here in the next few days. I have the seats and carpet removed already. What I need to know is what to do first. I have done a search and have not found the answer I need. How do you know where to cut? Do you lay the new pan in and trace around it? Then is it better to overlap the new one over the old or butt up to it? Thanks

 

http://personal.ecu.edu/boydd/tech/f...floorpans.html

 

That's a good one grruminator. I just love these Mustang Monthly tech articles though.
http://www.mustangmonthly.com/howto/...1_pan_replace/

 

I didn't even think to look there, in fact I just reread that article not too long ago!!

 

The hardest part for me on the floor pan i put in was not to get frustrated and start hurring! Watch out for brake and gas lines also when you are cutting and grinding! o and the "POR" stuff is good just dont put it where you plan on welding it splatters all over the place

 

Yeah, the POR 15 goes on after the floors are already welded in.

 

Its fun! Its Exciting! Its replacing floors in an old rusty car! okay well some of us enjoy it.. all good advice, great articles. Buttweld or lapjoints, personal preference, although a lapjoint can allow rust to form between the sheets if its a large overlap. In the automotive world of sheet metal, wetness between the sheets is not a good thing..

 

I recently completed the pans in my 66'. It's not that difficult and from tear down to completion ( this included a light sand and paint of the dash and rear quater panels, full interior replacement and custom package tray / front kicker panels with speakers. ) was 10 days. Mind you, I did this on a 15x15 concrete pad w/ a carport to keep the weather off of us. A sawzall and mig welder. Drill motor, dozen 1/16 and 1/8 drill bits and countless rivits.( With a plasma cutter and a lift, this could be done in much less time )

We drilled spot welds and cut on the tunnel. Was able to save parking brake brackets, however, had to fab up seatbelt brackets. Jsut lay the pan in place, use a sharpee marker to outline and remove the pan. use 1/2" masking tape below that line and cut out the tunnel. The 1/2" gave me room for adjustment when I started welding the new pan in.

Find a square, solid starting point. I used the rear spring shackle mounting plate as my starting point because if that was not square, I had other issues. I got the pan square and level using rivits and just started welding spot welds. Letting one area cool while I moved on to the other.

One suggestion ( this is in one of the MM articles as well ). Don't be afraid to drill 1/4" holes through the pan and frame rails where the trans cross membermeet. It's difficult to get the pan to lay down there and I used 1/4" shoulder bolts to pull the pan in place. You can either remove them and fill the holes or do as I did and just left them in and weld around them. IT also adds to the strength of the whole under structure.

Lastly, clean the new pans with a good grease remover prior to any primer/paint - undercoating. The supplier sends the pans with a thin coat of rust inhibiter and if you don't clean them first, nothing will adhere too them.

The best bit of advice I can give you is - do one side at a time and don't get frustrated. Also, don't be surprised to find toe kickers that need attention too. I thought I inspected mine good enough before starting to cut but when I got the pan out, I discovered the passanger side kicker to be in bad enough shape that I ended up replacing it too.