Just about any smallblock V-8 through the late 80's should be a bolt-in swap using the original front and rear mounting system. You might have to scrounge up a set of the old style ram's horn exhaust manifolds. I'm going to break with the crowd here, and reccomend a 305 engine. They're cheap (sometimes free), and with a stock rebuild other than flattop pistons and a slightly better cam, they produce plenty of power for a street machine. I've run them in claimer-class roundtrack racers, very successfully. The Comp Cams 260 degree High Energy cam, and a set of Speed-Pro Hypereutectic flattop pistons will get you the same power output as an early 327, especially if you use an Edelbrock dual-plane manifold and their AFB clone carburetor. it's streetable, even with a stock torque converter if you choose to go with an automatic trans, and reasonably good on gas mileage.
Jerry
