360 questions
How handy are you? How much $ do you have? That motor may be one rebuild away from being a real winner! A 360 is a fine motor even if it is not in race trim. All things being equal a 340 will beat the tar out of it but you don't NEED a fire breathing HEMI to have a good time. Since it was mounted in a truck the heads, intake etc were designed for truck duty so it may not be ideally suited for muscle car service; that need not deter you, though. Having a 360 around to trick-out while you use the 318 (another fine engine in its own right) could be a good project or maybe just drop it in. I'm not sure about the K-member and suspension upgrades you may need, but I say go for it.
Keep'em comming -LY