Had 4.10's installed....car tops out at 99mph??!!

[wantapony2001]

ok, i have a 99gt auto , i just had 4.10's installed about a month ago or so , i havent really got on the car much that much besides just darting off the line at lights and whatnot , anyway , i was on the highway alone and wanted to see if i lost top-end due to gear swap , the car was hitting rev limiter or speed governor at about 99mph, whats the deal ? when i had gears installed they also burnt me a chip to fix the speedo and they said they "set it up for speed" . can anyone tell me why im not going any faster...? thanks