Correcting the Original Kit

One of the first things that a careful builder notices about the venerated 1964 Monogram Predicta kit is that the kit body doesn’t match the photos of the car. Though the model generally resembles Darryl’s car, several fundamental proportional and measurement errors mar the kit. Without access to the construction phase and later photos, even a highly-motivated vintage or contemporary builder — wanting to build an accurate scale model — wouldn’t have enough information to catch and correct the dimensional errors in the original kit and certainly couldn’t build such an authentic scale miniature from the kit.

However, here at the headquarters of The Predicta Project, we understand where the problems are in the kit. The dozens of photos we have, combined with digital photo analysis and Starbird’s generously-supplied measurements, have revealed precisely where the errors occurred in the original kit. Darryl’s generously-provided key measurements have permitted us to exactly locate where the dimensions and shapes in the original hobby kit body were in error. On a technical level, these actual measurements have helped us avoid the parallax problem of relying only upon what appear to be profile images but which aren’t true profile images because they were shot with a single camera at one fixed location.

With extensive data in hand, I’m going to master a correct 1/24-scale Predicta body for the car so that we can build our phantom-enhanced 1964-era kit that will permit us to step out and build the rest of the models for this project. The revised/corrected master body and other parts will be resin kits by Norm Veber.

We, at the Predicta Project, express our profound thanks to Starbird who has graciously provided the dimensional information taken directly from the car, and to Steve Roullier for creating the “measurement photos” that graphically illustrate the differences between the kit and the car. What follows is a photo essay list of the most prominent dimensional problems with the kit. As work starts on creating an accurate 1/24 scale body, we’ll feature here photos about the process of constructing an accurate body shell and other related parts.

This is a sample of the many photos sent to Darryl, when annotated, that requested actual measurements from the car.

Measure.1 Measure.2 Measure.3 Measure.4

Rear Deck/Rear Grille:

The fins aren’t correctly angled. The fin root is located too far outboard in the kit, and doesn’t angle steeply enough with respect to a perpendicular line drawn vertically through the center of the body. The fin (to the trailing edge of the door) needs to be cut loose from the kit body, and tipped at a great angle to the kit body and then re-attached.

One of the biggest, if not the most subtle, problems with the accuracy of the kit is that the rear deck doesn’t depict the strongly angled trailing edge of the “trunk.” The “V” shape doesn’t appear in the kit, and the inward taper of the rear deck, also isn’t in the kit.
Here’s an original construction photos showing how Starbird trimmed a trimmed first-gen Thunderbird hood to the back deck of the car. Note the gentle curved convex shape of the hood which survives to this day and which isn’t found in the kit.
Note, in this photo taken in 1963, how the convex shape, with the subtle peak, can be easily seen. Case closed!
The rear grille isn’t wide enough. The full size shell is 64.5″ full size; the kit’s grille is 60.84″ (if full size). Another problem is that the rear grille isn’t wide enough in the kit. In scale, it should be 2.25″ and it’s only 2.20″ for a full-size difference of 1.20″ Yeah, that’s enough to fix it.

Rear Quarter Panel:

The rear wheel well at the bottom isn’t wide enough. The full scale measurement is 30.5″ or 1.25″ in scale where the kit dimension is 1.105″ meaning a full scale shortfall of .15″ in scale or 3.60″ full size.

The distance between the rearward most tip of the fin to the base of the bubble (not the bubble ring) should be 2.05″ in 1/24 scale but is, in fact, 1.810″ on the model which corresponds to 43.44″ and it should be 49″ in full scale. This supports our view that the entire bubble top assembly is set much too far rearward on the body.

Bubble Top: Mark Benton has also pointed out that the bubble top sits too far rearward on the model.


Mark is onto something here: it appears that the rearmost extension of the bubble top is just slightly behind the centerline of the rear axle. By contrast, check out the location of the bubble on the kit body. We’ll move the whole bubble top assembly forward.

The bubble top also isn’t quite wide enough: It should 54″ at its widest part but is only 52.80 for a difference of .05 in scale. The final problem with the bubble top is that the kit piece if too tall. Darryl advises that the bubble top, at its tallest, is 16″ but the kit part presents a bubble that is 18.72″   These two dimensional problems mean that we’ll be making a new bubble top!

Side of Body:

The incut character line on the side of the body (at the base of the fins) isn’t deep enough, and is located too high in the body. The deeply radiused, front-to-back, incut needs to be moved lower and incut more deeply into the body. 

The kit doesn’t present the subtle round shape that runs along the bottom of the rocker panel. When he restyled the car in 1963, Darryl welded a piece of steel tubing along the bottom of the rocker panel, and then molded that shape into the leading edge of the rear wheel well, and the trailing edge of the front wheel well. We’ll present this shape, of course.
The doors aren’t long enough. They should be 1.745″ at the widest but are only 1.680″ on the kit, for a difference of .065″ in 1/24 scale or 1.56″ full size.

Front Fender:

The front grille is mounted too high, and the fender/hood line above the character line is correspondingly too high, also. Additionally, the side view shows the characterline that has a gentle convex radius toward the front of the car; finally straightening out at the back of the front fender: The kit doesn’t include this feature.

Front Clip (profile)/Headlight and Grille:

The distance from the forward-most edge of the door and the bottom of the front wheel well is in error. The distance from the back of the front wheel well to the forward-most edge of the door should be 1.15″ but is 1.246″ for a difference of .09 or 2.16″ in full scale.

The hood is the right length, but it is mounted too far rearward which supports the analysis that the bubble top is also positioned too far rearward. The distance between the leading edge of the hood to the forward most part of the front fender is correspondingly too long on the kit. So, we’re going to move the hood/bubble top assembly forward to correspond to Starbird’s measurements.

The height of the front fender, to the top of the fender from the upper line of the wheel well (at its center) should be .148″ but is .198″ in the kit for a difference of .05″ or full size difference of 1.22″ in 1:1 scale.

The headlight pods are almost exactly correct with only .006 marking the difference in the scale measurement. However, the distance between the inside of the headlight pods is off by 2.30″ full size suggesting that the front grille shell is too narrow. We’ll widen it a bit and then cut wider grille bars.

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