I am rebuilding my 63 and have been searching for a 409 to replace the stock 327. I bought an engine before doing my homework and it turned out to be a 348. Now I have located another engine but am unsure what it is. The owner tells me it was a replacement engine for a 409 that his father had trouble with in 64. The casting # on the block shows a 348 truck. Dipstick is on the pass. side and has a D shaped crank. The heads are 409 252 hp. and I had no luck with the intake or exhaust manifold #'s. What is it? Can anyone help me from wasting my money?