[pjmoreland]

I had a 67 with a 250. It had 4:10 gears and an overdrive from the factory. That engine was quite wimpy, but it got good gas mileage on the highway, which may have been mostly because of the overdrive. I installed Clifford headers combined into a single 2-1/2" pipe and a Flowmaster 40 series muffler. Sounded like a Honda Civic with aftermarket exhaust. I also installed a Clifford intake manifold and a tiny Holley four-barrel carburetor. Those add-ons did wake it up a bit, and I drove it that way for a couple of years. I ended up installing a mild 350 in it, and I was blown away by the difference in performance.