duels on stock 225

My 69 WSS still has it's original exhaust system on it and the rear portion over the rear-end is starting to have more in common with Swiss cheese than a tailpipe and I want to add the other side and cross over as far up as I can( it has one tip and I would like both). first question is: I noticed that the gas tank is offset, was the tank for a car with duel exhaust different? Next: What small V8 used a dual system that was smaller than 2.25.
You can buy 2.25 parts but it just seem over kill on a stock 225. This car only has 80,000 on it and is bone stock and I'd like to keep it as stock looking as I can.
Thanks,
Larry