Magnum Exhaust Port Dilema

Because I have these already....... lol
Well that makes sense.....but you have a lot of meat to cut. LOL Enlarging the exit won't help if you don't enlarge the whole exhaust path. Sell those and buy some heads with a large exhaust port?? You can get a bare set of 360 heads pretty cheap from any motor machine shop. They might even make a trade??