MK IV GT40 tubs were built in 1966
Ken Miles died in fall of 1966 testing a MK IV
The car has met Goodwoods criteria
The MKIV did not exist in 1966.
The J-car was official called 'GTP'
Ken miles J-2 Can Am version and the first J-1 Bread van Le mans trial were not MkIV's but J-cars
J-3 although constructed as a J car in October 1966 was and rebodied as a MKIV after February 1967
J-4 the Sebring winner was constructed on a Breadvan J car mix chassis in January 1967
J-5 was the first car to be scrathbuilt as a MKIV as well as being the 1967 Le Mans winner
J-6 this car finished fourth in the 1967 Le Mans
J-7 and J-8 were the Holman and Moody 1967 entries both DNF J-6 crashed and J-7 retired.
Like jmvelez has said J-9 was not built until August 1967 as a G-7A Can Am car complete with deyhedyral wing.
According to Ronnies Spains book J-9 was unraced and J-10, was the G-7A car that competed unsucessfully in races before crashing.Thus ending the J/MKIV saga.
jmvelez true the first twelve preproduction cars were called Ford GT's The production cars had chassis numbers GT40P/. The Ford GT40 was official homologated for group 4 racing in May 1965 under that name.
Fords whole original project inception in 1963 was Total performance. Ford GT could be applied to all the cars in it. Except the MKIV were called Ford MKIV's But there are referred to as GT40 which they are not!
Regards Allan