Two main issues,
1) Shielding, and
2) Filtering of the power and keying lead wires.
Look inside any radio with a factory built-in amplifier like the Clear Channel AR, 2970, 2990/95, Connex 6900, and you'll find a metal shield that encloses the amplifier circuits. The wires leading into it are properly filtered.
Mimic that part of the setup, and it should perform like the factory-installed types.
Leave that stuff out, and you'll have...... a Stinger... Not to mention all the RF headaches that the lack of a shield and filtering will bring about.
Just got to see a Connex 4300 on the inside. Uses a single 2SC2290 as a final in place of the 2SC2312. Cute, gets around 80 Watts peak with a 20 Watt carrier.
They mount the 2290 in place of the stock final, with a small circuit board around the 2290.
Gotta wonder how long before somebody comes up with a "retrofit" kit to put this in your Galaxy DX-33?
73