Slant 6 Help

Ditto to Furiousvip's suggestion, and I'd go with even lower gears. If you absolutely must modify the engine, install a two barrel Super Six setup. Then if you do change to a V8, you can easily sell the SS carb and manifold, and might even make a profit. That said, I would keep the slant. If you must have V8 power, swap cars, not the engine.