He was talking about the AMR wheels.
They weigh a lot, according to the Mustang guys. But the American Muscle website has weights on the 19's, here's the actual complete chart actually:
18X8 Chrome AMR (94-12) 23.80
18X9 Chrome AMR (94-12) 24.70
18X10 Chrome AMR (94-12) 26.65
19X8.5 Chrome AMR (94-12) 26.80
19X9.5 Chrome AMR (05-12) 27.10
18X8 Matte Black Machined AMR (94-12) 23.50
18X9 Matte Black Machined AMR (94-12) 23.80
18X10 Matte Black Machined AMR (94-12) 24.65
19X8.5 Matte Black Machined AMR (94-12) 26.15
19X9.5 Matte Black Machined AMR (05-12) 26.85
18X8 Charcoal AMR (94-12) 23.60
18X9 Charcoal AMR (94-12) 24.55
18X10 Charcoal AMR (94-12) 25.35
19X8.5 Charcoal AMR (94-12) 26.25
19X9.5 Charcoal AMR (05-12) 26.95
Keep in mind, you can get a better quality similar wheel from Avant Garde, or other options.