Number matching questions
LS23H72 , right ?
The 1967 "GT+S" was available only with a 383 .
Production started in Spring 1967 (~April ) .
Can't *completely* blame your insurance co for not knowing about this esoteric model . For many years , there was a bone-of-contention that there was no such an animal as a factory-produced big block 1967 Dart ; that's ostensibly been proven wrong :-)
The first '67 GT+S saw was in 1986 / 1987 . A convertible none-the-less ! LS27H72 .