[Doug]

I saw the car on Ebay a few times and wondered about how the rear end was set up. The car is very nice!

Attached for reference are copies of a couple of pages out of the car's factory BODY SHOP MANUAL.

Paragraph "j" on page 11-4 of the car's BODY SHOP MANUAL has this note:
".....NOTE: Center of the compartment pan left side assembly (gas tank filler neck side) is located 1 5/16 inches further from body centerline than center of compartment pan right side rail assembly....."

The above note refers to the “gas tank filler neck side“. In previous years the same floor pan was used in both cars and station wagons and gas was filled from the side on both the cars and wagons, necessitating the frame rail offset design. In 63, the same floor pan was used for both cars and station wagons but only the wagons were filled from the side with the cars having the gas filler in the center of the rear of the car.

The original rear tread/track width of the car is 58 inches. The rear tread/track width of the TA rear end is 60 inches so you already are “too wide”.

You indicate the front mounts of the leafs are mounted “centered” on the frame rails, equal distance from each other. The centerline of car can be determined by measuring equal distance from corresponding points on the frame rails. Note that the driveshaft floor pan tunnel for these cars is "offset" about an inch to the left (driver side) and if one uses the centerline of that tunnel, it is not "centerline of car".

With reference to the chassis dimension information drawing on page 11-2 of the car's BODY SHOP MANUAL, the overall distance (dimension "X") between the frame rail centerlines where your leaf spring shackles mount is 42-1/32 inches as shown in the chart on page 11-3. Allowing for the driver side offset of 1-5/16 inches, that means the centerline of your passenger side spring (frame rail) is 20-23/64 inches (effectively 20-3/8 inches) from "centerline of car".

Again, with reference to the chassis dimension information drawing on page 11-2 of the car's BODY SHOP MANUAL, at about the point where your leaf spring front mounts are mounted, the overall distance (dimension "P") between the frame rail centerlines shackles mount is 40-5/32 inches. Or, in other words, the front mounts are 20-5/64 inches off centerline of car.

Accordingly, that means the passenger side front mount centerline is 9/32 inches (20-23/64 inches minus 20-5/64 inches equals 18/64 inches (9/32 inches)) closer to centerline car than the centerline of the passenger side rear shackle mount is to centerline of car.

From your pictures, the passenger side spring "appears" to be straightly parallel with centerline of car. However, if it is 9/32 inches out of alignment, it would be difficult to see.

I would suggest you do a bunch of measuring of the distances between your spring mounts on both ends, confirming that the dimensions are relative to the centerline of car and confirming, at least, whether or not the passenger side spring is parallel to the centerline of car.

Your pictures indicate that you have tires that are much wider than stock tires and you have rims of wider backspacing. I don’t know what the factory distance is between the spring perches on the TA rear end. To achieve the space needed for the wide/backspaced tires may have required relocation of the spring perches closer together than the factory spacing.

The frame rail where your shackles mount is only 2.25 inches wide. I don’t know what the width is of your leaf spring, I assume it is 2.5 inches but may be wider. In any case, your shackle straps are going to be wider apart top-to-bottom (unless some spacer is used at the top to compensate).

Depending on what your measuring finds out for the passenger side, it appears that you can substantially correct the alignment by simply cutting your shackle straps about an inch or so (whatever the bolt hole spacing is at the bottom of the strap) above the bottom bolt, lapping the bottom pieces on the INSIDE (toward centerline of car side) of the top pieces and welding them back together.

For the driver side, it appears that you can substantially correct the alignment by simply cutting your shackle straps and lapping the bottom pieces on the OUTSIDE (away from centerline of car side) of the top pieces and welding them back together.

Your photo of the driver side shackle mount appears to show the bolt not going through the rail squarely. If that is the case, it should be corrected when you work on the car. Similarly, the frame rail metal is “thin” and you may want to plate each side where the bolts go through.

Keep us posted, work safe!

Good luck!

P.S. I hope my math is close to correct!