I have recently acquired a 63 Valiant that I am restoring for my sister in law. Has fairly significant rod knock when running. I have a good running
slant six out of a mid 70's Volare. My quandry is this, should I swap motors and is there anything significant as far as differences that I need to be aware of; or do I attempt to locate the rod and replace it. The engine seems to run fairly well with the exception of the rod issue. I am just trying to get some additional insight. Thanks!

biggest issues will be:

crank register is bigger on the 70s engine

make sure you have a 225 in the 63. otherwise the head pipe will be too short.

sb

How many miles are on the 63 engine?
Have you ever heard the 77+ engine run?

To fix the 63 engine is basicly an overhaul job.
The engine comes out and "torn down", the head and the crankshaft will be removed along with at least one piston assembly. The "now that I am in here this far" thinking starts to kick- in... Once one Con rod - Piston assembly is out, the other 5 come out with-in minutes.
May as well install a new set of rings to go with the new bearings in the crank kit.
And once you see the condition of the timing chain and the cam, you will want to replace thoses parts. And with a new bottom-end, a new oil pump is a "no brainer". Now the cylinder head... you get the idea.

To swap in any other used engine, you need to be sure the replacement engine is in good condition. If you have heard it run then you are ahead of the game. If it's a "the guy said it runs great", you better do some checking or better yet, run it out of the car.
If you go with the later engine, you will need to swap the 63's oil pan and pick-up tube onto it and use the later flex plate with the special crank hub adaptor bushing.
DD

That's EXACTLY what I would have said. Davey

Thanks, I appreciate the input. I actually did have the opportunity to see and listen to the later model engine before pulling it. The only thing I didn't grab was the piece between the flywheel and the torque converter. I think I will forge ahead with the motor swap instead of the rebuild as time is of the essence.

The "piece between the engine and the torque converter" is the flex plate. You'll need it. And, as has been mentioned, you will need to use the ¼" annular adaptor ring in the later engine's crankshaft rear flange counterbore—even if you don't think you'll need it. You can get the ring from Pat "Torqueflite Patty" Blais, tflitepatty@verizon.net . Use the 1963 oil pan and pickup pipe, the 1963 engine mount assemblies complete, and the 1963 carburetor. As long as the later engine is out, you will probably want to change the timing chain and sprockets; that '78 engine has the nylon-over-aluminum cam sprocket and low-bid chain.

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