Be aware that there are no standard offsets on the VHF public safety frequencies in the US. Frequencies are assigned on an "as available" basis so the repeater input and output frequencies are not a standard amount apart, even for a single agency with two or more repeaters. For example, one may have the output on 155.25 with an input of 158.75 while their other may have the output on 156.50 with an input of 154.15.
This is in stark difference to the ham repeaters where they are mostly a standard 600 KHz apart. Also most UHF repeaters (both ham and commercial) are a standard 5 MHz apart (although there is a range of commercial frequencies where this is only 3 MHz).