right there is a problem........chrysler used price classes on all product lines and that format remained constant .....L, M, H, P, S was the format and this is the second letter on your VIN number
L= low (base swinger)
M=Medium (swinger 340)
H=High (custom)
P=Premium (GT)
S= Special (GTS)
so to say a GT was lesser than a swinger 340 as far as trim and price class that is not true.....the base price of the GT was much higher bcoz of it "standard options" which in the case would be "convenience options" Buckets came standard with GT so were light packages ....ornate steering wheel, Dual horns and the like.
to say a GT is lesser from a performance point of view .....absolutely GT came with non-performance engines, hence why i said earlier that a GT convertible was a good parade car.......Pretty......very Fast.....not likely.