John, This one is pretty easy and I'm glad I came accross you post at last. These cars will be fairly easy to duplicate with the Revell '69 Charger, Revell '69 Landy Dart, Revell '67 Charger and maybe substitutes in the '67 Revell GTX, all now out.
The Charger will be your base. The '69 Chargers Landy ran interchangeably had 440 4 bbls. or Hemis, each with automatics (torqueflites) or 4 speeds. It depended on where Chrysler wanted him to be on a given weekend, what national record needed to be set, etc. They ran headers without exhaust systems, Crager S/S mags, no roll cages, stock buckets and back seats. The Revell '69 Dart has a 440 automatic which put is as stated on the box in SS E Automatic, and that has the automatic that can be cut and pasted on the Hemi for any of these cars if you wish. It has headers set up for the 440 heads. The stock Charger 440 is a 4 speed, but could be used with the headers. But probably of most use for the Charger will be the '67 Revell Charger kit. It has the best Cragers out now, and the slicks you need, plus headers to fit the hemi and a cool can, which was filled with dry ice and the fuel line run through it before it got to the carbs. Beyond this, the seats should be fitted with large racing seat belts and buckles. There should be a large tachometer on the dash, furnished in the 67, and some accessorie guages underneath. For the 4 speed you should have a hurst floor shift, the automatic would be a column shift with a reverse pattern downward, 1-2-3 instead of 3-2-1 so you wouldn't get too excited and go past 3 to reverse. All these cars need a small floor mounted fire extinguisher, that goes for the Darts too.
The last big part of the Charger is the scoop. Early in the year, Dandy Dick used what is called an A990 Hemi scoop regardless. This is the scoop in the 67 Charger and GTX. The GTX has all the same parts as the Charger but has Keystone Mags since it was designed as a Sox and Martin Drag Car. Later the car featured what is know as the "Landy" scoop which is very similar to a Mopar Six Pack style scoop. This exact scoop is available for only about $5 or so from Competition Resins who have a web site or Slixx decals' site, which carries not only decals you will need plus Competition Resins parts. As far as classes go, the Hemi Charger would be in SS/D with an A added if an automatic, and as I recall SS/H with the 440. It also ran in various Modified Production catagories, MP/ with both set ups.
The Dart is a '69 model as is, but could easily be modified to a '68 with the addition of such things as small side marker lights. The engine transmission combos would be above. These kits were all designed very closely and most of the parts are just a drop in exchange. To do the '68 Hemi as you wish, you would substitue the engine, headers, etc from the Charger as described. The rear wheel wells would be opened up just slightly. Again there is no roll cage, however, there is no rear seat which should be cut out and or covered up with sheet plastic and whatever you would use to similate black carpeting. The front seats should be Dodge van units, found in any of the Lindberg '64 Dodge or Plymouth kits, or the Little Red Wagon. Shifters would be the same as described for the Charger respectively. The Hemi will also need the cross ram manifold, used in the Lindberg 64 Dodge kits. I believe this is also found in the AMT ERTL 68 and 69 Plymouth Kits which might be useful in the '73 Dart which I'll talk about in a minute. I think Competition Resins is another source as it would be for the correct Hemi scoop. That can also be found in the '69 AMT exMPC Barracuda. This car would be a SS/B competitor, believe it or not, A was reserved for big block Corvettes and such, eesh. Again, use the cool can, tack, find a fire extinguisher and etc.
The 73 will be a little more complex but not unbearable so. The hysterically packaged AMT ERTL 75 Duster is what you need. Its not. It's a Dart Sport all the way, grille, taillights, everything. The 73 74 grille was slighly different but not greatly, with your research materials which I'll get to in a minute, nothing that a little paint and xacto knife work might not take care of. There was an article in Scale Auto Mag. about 8 months ago where Clay Kemp built up the Mopar Missle which is the exact same car. His involved a lot of aftermarket and cutting and fitting however. The AMT kit does not contain the tubbed 4 point rear end with wheelie bars or Lenco transmission for instance, and he tells you where to get these. But if the bottom side isn't so crucial, just use the stock leaf springs and etc. Thats all the original MPC kits of these pro stocks used, and thats essentially what this is. The Hemi has the exact tunnel ram intake and holley dominators that you need as well as good two piece headers. The transmission is a simple 4 speed though. The only engine mod I would do is drill out the spark plug holes and then add an extra twin hole to each one right next to it. Then drill the front of the block and add another distributor right next to the existing one, another coil and presto, instant 16 plug Hemi as pioneered by Dandy Dick himself. You will need Center Line "super trick" wheels, those are the smooth ones with just small bolt detail around the beads and no holes or slots. Many kits had these in the 70's 80's and 90's, most recently the AMT ex MPC 74 GTX has a nice set as its optional wheels. Use skinnier street tires from alsmost any source on the front, and medium sized slicks, which should require too much chassis or body trimming if any on the rear and you are good to go. Again Competition Resins is a fairly cheap alternative if you don't have spares. Interior wise you need to remove the rear seat from the interior tub and replace with sheet plastic or cover it up with sheet plastic. You will need a cage on this one, and though I know of none for sale in kit or aftermarket form, its a simple one to do with Evergreen or Plastruct plastic tubing of a size that looks in scale to you. The rear part is the standard roll bar hoop. Atraching to the front of it is a hoop which just follows the inside of the roof to close to the top of the windshield. It would attach to the outer top rear edges of the roll bar behind the seats. Then run two downtubes from the front outsid edges of the top tube down to the floor. These should kind of slant forward as they come down to match the angle of the a pillars as closely as possible and come tight in front of the dash. Then just add one diagonal bar from about shoulder height on the roll bar in back of the seats forward to meet at the floor with the front down tubes. Thats it. The seats should be lightweight fiberglass drag buckets however. Therse are in the aforemention AMT Mopar 68 69 0r 70 prostreet kits, and are like the seats in Model King short track Stock Car and Modified Stock Car Circle track kits. They only have one of course. Another good sourse is the 72 GTO AMT ex MPC kit, which also has a really neat extra, a drag strip christmas tree starting light set up, in scale that is great. Great to display with the model or in a diorama. Believe me, its worth the price of admission. In it too is a small piece, I think chrome which looks kind of like two small ignition coils joined in the middle to look like an H. This is an electric fuel pump which could be attached to the side of the gas tanks in all these kits, the above Charger and Darts too. Then I would coverf the stock guages with a flat piece of plastic and put some gauge decals of small accessorie decals on it. Again use a tach on top of the dash. The shift lever on this would have a small short throw shifter on top of a small box on the floor which would be about half the size of a kit battery. If you use a Lenco transmission or are faking it, you need 5 really small shift levers to fan kind of horizontally out of the box. I think straight pins would work well for this.
As for a scoop, the rather large ungainly, bulbous looking one in the kit is about right! Otherwise, see Competition Resins again.
Research is plentiful. There is an actually Dick Landy sight yet with many photos, dicklandy.com and a great sight for any of these cars or ones like them, prostockhemi.com. The latter goes back to the mid 6os as well as up through the mid 70s.
There will be a drop down box next to a search indicator. Drop it down and you'll see all the mopar racers names. Dick Landy will show up alphabetically by his first name. Hit this and you'll get 3 pages of all the cars you are wanting to build. Use them for marking and decal features, some of the small details, and you are good to go!
I know this will help, good luck and above all have fun! Let me know that you got this and give me some progress reports if you would. I'm really interested.
Dave Bayer firstname.lastname@example.org