Gary,
The Ford GT family is kind of a passion for me, just like Detroit engines are for you. You've asked for a long story. There are a lot of books out there - I will try to just hit the high points.
The Ford GT family is an offshoot of the Lola GT coupe designed by Eric Broadley in 1963 in England with the 260 Ford v-8. (Every engine I mention will be pushrod unless I say otherwise). Ford took that as a starting point when they decided to get into racing and build the original Ford GT (289 engine)as we know it. That car first raced in 1964. They also built two as open topped roadsters. Ferrari won at Le Mans, and they won the Manufacturers' Championship.
The original design car was modeled by IMC and the car as first raced was kitted by Aurora, later repopped by Monogram and Revell. IMC provided the 255 DOHC engine in the kit, but that was never raced. Mini Exotics makes a relatively reasonablly priced resin body for the roadster.
In 1965, They won a single race, at Daytona. The 289 Ford GTs continued to race, but Ford also beefed up a pair of cars and stuck 427 engines in them. They raced both engines at Le Mans and ran fast and broke. Ferrari won again.
A Japanese company kitted the Daytona winner (was it Imai?) the kit was really poor.
Ford then got very, very serious about development, and for 1966 delivered the Ford GT Mk II with the 427 engine, now fully tested and ready to go. Holman Moody and Shelby American each prepared cars for Daytona and Sebring, and the Fords won. At Le Mans, there were eight cars, with Alan Mann having two more Mk II cars. This was the famous 1-2-3 finish. (second place was a light blue car prepared by Holman Moody, but not sponsored by Gulf) Also, the 289-engined cars were now in the hands of private owners and raced all over in 1966, and called either plain Ford GT, or starting to be called GT40, because they were 40" tall. Nobody called them Ford GT Mk I. This was the year of the Chapparal 2D coupe. Ferrari did not win.
IMC kitted the MKII, as well as Fujimi, which was later reboxed by Revell and Testors. But that Mk II kit was only accurate for Le Mans, no matter what boxart shows.
The red #1 Sebring winner was a roadster called the X-1, a really serious difference from a standar Mk II.
For 1967, Ford needed to find a way to "take it up a notch". The J-Car was a new technology chassis. During testing in the off season, the great driver Ken Miles, who had won at Sebring and Daytona in the Mk II in 1966, was killed. The cars were further modified, and the result was now known as the Mk IV. (The MK III was a street version of the 289 Ford GT) The Mk IV raced at Sebring (2 cars) and it won, and at Le Mans (four cars) and it won. Mk IIB cars, which were slighly updated MK IIs, ran throughout 1967, and didn't do very well against the up-to-date Ferraris. This was the year of the Chapparal 2F coupe.
MPC kitted the Sebrig Mk IV (That kit is gone now - they cannibalized it to make the Hardcastle & McCormick Coyote Special.
IMC (later repopped by Union) kitted the Le Mans Mk IV.
Fujimi has kitted some of the private GT40s.
At the end of the 1967 season, the big 7 liter (427 cubic inch) engines were banned. 5 liter (302) was the max size. Ford factory involvement pulled out.
For 1968, Gulf sponsored the John Wyer racing team, which further developed the GT40 with the 302 engine, as well as the Mirage, which was supposed to be a lightweight version of the GT40, but never very successful. In 1968 and 1969, Golf entered three-car teams of GT40s at Le Mans, and won with the very same car (chassis #1075) both years.
Fujimi kitted this chassis#1075.
And the big honkin' Trumpeter kit is the 1966 LeMans winning #2 Ford GT Mk II, chassis #1046.
Sorry to be so long-winded about my favorite subject in the whole world. You asked.
Rick