70 RR Floorpan Install Question

[BPBP440]

I leveled the car and supported it prior to cutting out the full floorpan and rear footwells. What I did not do was take reference shop floor to floorpan measurements at different locations. When mocking up the new AMD 3 piece floor (full front and LH/RH Footwells), it seems like getting the proper floor height front to back could be arbitrary. Any advice on getting the floor back in the right height location front to back.

 

[SgtLee511]

I installed my AMD front pan and the rear foot pans a few months ago, pretty mutch just get er done. The pans sat in place without mutch force having to be applied, Starting at the firewall, I just used a few self tapping screws to gradually bring the frame braces and pan together welding a few spot welds here and there to mate the two together. I used some vice grips or C clamps as needed. I just completed my rear underseat pan and found it to be the only challenging pan, as I also replaced my inner rear fender wells. Starting on my Trunk Pan when it arrives next weekend. If you supported the car well, I cant see anything shifting, mine fit very well I did not have to trim anything, I had used spot weld cutters to cut out the old welds on the floor, in a few of those spots I inadvertently cut a few holes into the floor bracing, I used a few nut, bolt and washers to pull the pan down in those spots before spot welding. I'm in trouble if those measurements are needed. Good Luck these pans are mutch easier than one would think. I forgot that ten pound hammer worked well at times LOL

 

[WileE]

It seems you prepared well, if the unibody is supported & leveled. The key to this type of job, as well as similar metal replacements, is when you remove the replacement part, nothing moves.

 

[BPBP440]

Thank a for the responses. I have already fit the pans and pulled them back out to drill the holes for plug welding. What I noticed was with the three pieces of floorpan coming together, I could influence the height from the floor at that point considerably. Felt to me like with a jack underneath, lifting the point they all came together resulted in a better fit. That's what leads to my question. Perhaps I am being overly concerned about the details...has happened before.

 

[WileE]

It's difficult to comment without visual, but generally you fit the panel to the existing structure, do not bend any rails, crossmembers, etc.

 

[Hemirunner]

Considering the way the floor goes in and the fact that it sits on the rockers, it should set itself in place once drawn down on the crossmember and floor support brackets and fitted to the rear floor pan.

 

[moper]

I've had to use a floor jack to get them to fit properly before. The areas at the hump are unsopported, and the pans tend to sag. Plus the floor itself can bend during shipping (on their sides on the box). So I'd screw the parts in temperary, then jack up the floor with a wood block up in the tunnel at the rear of the front full pan. Then fit the rear pans based on that. That's how I do them.

 

[BPBP440]

I've had to use a floor jack to get them to fit properly before. The areas at the hump are unsopported, and the pans tend to sag. Plus the floor itself can bend during shipping (on their sides on the box). So I'd screw the parts in temperary, then jack up the floor with a wood block up in the tunnel at the rear of the front full pan. Then fit the rear pans based on that. That's how I do them.

The sag in the unsupported area is exactly what I am talking about, thanks for explaining it better than I did. So your method is what I did upon initial fitment and I was wondering if there was a reference point to know when the amount of hump jacking (that sounds all wrong) is enough. Sounds like not, but if so I would love to know.

 

[gdrill]

I noticed the same effect in my challenger. I could take some measurements on my rr from frame rails to floor and then middle of hump to floor for you tomorrow eve. That will give the difference to work from the rails.

 

[moper]

I'm sure the factory did it in a jig. The first time I did it I eyeballed it and it was fine. Subsequent times I measured before I cut the old floor out and it varied car-to-car by an inch or less. It's not rocket science so don't feel it has to be exact. It just has to be close.

 

[SgtLee511]

Yes, I also used a jack a few times.

 

[gdrill]

I went out and measured my RR and this is what I found. I measured my frame rails right near the front of them at the first drain hole. They are sitting at 11" from the concrete. Then I measured up to the highest point in the floor hump and it is 20 3/4" from the concrete. So basically the floor's highest point sits 9 3/4" above the bottom of the rear frame rails. Make sense? Of course, as mentioned, I'm sure there were variables, but this is how my factory floor sits.

 

[BPBP440]

I went out and measured my RR and this is what I found. I measured my frame rails right near the front of them at the first drain hole. They are sitting at 11" from the concrete. Then I measured up to the highest point in the floor hump and it is 20 3/4" from the concrete. So basically the floor's highest point sits 9 3/4" above the bottom of the rear frame rails. Make sense? Of course, as mentioned, I'm sure there were variables, but this is how my factory floor sits.

That is awesome that you went and measured that for me, greatly appreciated. I will absolutely use those numbers to make sure I am in the right ballpark. Thanks again.

 

[383man]

When I put the front floor pans in my 63 I had the car sitting on the four tires just as I would drive it after I set the height I wanted the car to be. Then I used my floor jacks and put two on each side right up to the rocker panel seems but did not lift the car any. I just put the jacks there to keep the car supported in that same posistion while I removed and replaced the front floor pans. Ron