you'd need to look at the entire amp design first before you mod, you need to look at the class, the power supply and the rails.

Some amps might benefit from larger chips, some benefit from a beefier power supply or more caps.

All comes down to amp design for which you'd need the schematics for it.

I've got a radio out of a 2002 I'll open and take a look for you if you'd like.