408 Engine Question

[Ronald G. Stephenson]

Some would advise to immediately seek out the original engine of that displacement. The 313 was a Chrysler Canadian engine, and the ubigutious 318 were manufactured by the millions. Your 340 is a small block Chrysler out of he same family, but is what is referred to as an LA engine. Your car, being a 1964 had one of the early small blocks and it was a different family. The idea of a six-pack on it steps up the performance substantially over the old engine, but if you choose to revert back to original, that will not be a hard thing to do. It all depends upon what you want. I would keep the 340 in there and enjoy the performance. I would also source an old 313, and set it aside in case you get the itch for 'originality' or if you decide to sell the car. The torqueflite automatic bolts behind both engines. Enjoy!