Neil here's a couple of shots of the decklid, although not the original one, which was on my car when it arrived back in early '94 with tape measure added. The glue residue suggests an R/T emblem was on at one time but no sign of residue from the Challenger emblem. When the time comes for my car i'll add the Challenger emblem, lining up the bottom of 'Challenger' with the bottom of the R in 'R/T'
The top of the 'R' is 3 inches from the bottom of the decklid.
The bottom driver side corner of the 'R' is 6 1/4 inches from the right side of the decklid.