put a switch to turn the amp off on the 98 and amp choices are numerous. but the 98 isn't the best choice for running boxes.
But to get real gain going from 250/300 watts you need to make a huge jump in out put power.
A 4 pill ain't gonna do squat.
Really.
A 8 pill will get you some, but if you want to see a big difference on a s meter, and to get any of that warm fuzzy feel good you need 16.
And almost anything that big is a class C comp box so your screwed on SSB unless you know a builder that can put a GOOD bias setup in it.
I have seen lots of CB guys do this.
Buy a 350
Not happy.
Buy a 500
Not happy.
Buy a 8 pill
Meh
Wish they had something bigger.
If you got in the corner, mauling or bawling fever, should have bought the 16 in the first place and saved a lot of money/time.
Cutting the internal amp off to run a amp is just a waste IMHO.
73
Jeff