Handling ID Changes Crash GTAV and RPH

As the title says. I have experience with how a fair amount of code works so for a while I was managing just fine with base game handling IDs. Well, I want to update the handling of my vehicles to a better handling line that allows higher speed. Found a stock car in GTA for both the charger and SUV variants of my police mods. Specifically the Buffalo STX and Baller ST (buffalo4 and baller7 respectively). Previously all chargers ran "buffalo" and SUVs ran "baller2" handling IDs in my code. Buffalo obviously made sense but baller2 had a faster 0-60, cornering was better and high end speed was 30 mph faster than any other SUV type. The Baller ST (baller7) essentially had negligibly worse handling and a buff in higher end speed so I wanted to add that. Same story with Buffalo STX (buffalo4). Game crashes instantly after selecting "Load Story Mode with Rage" option. I previously had ran into this months before and simply picked launch patch vehicle handling IDs which always will work. I really want to bring in the better handling lines to make my cars better. Would I have to hunt down the code for these DLC vehicles and place it into the core mods files or am I just SOL?

FYI: The speed and handling of what I have right now is decently good, and if I wanted more speed at the same handling I could just use the trainer to buff the engine and torque as needed but I would like my compatriots to also be able to match speed and be as quick as me. Not a deal breaker regardless.