The later 270 and 302(1955 to the end) usesed a funky engine mount that bolted to the front at the sides. You can still use these motors, but you have to change out the front timing plate with an earlier chevy or gmc motor for it to bolt into your chasis. The Military 302s would need some machine work, but nothing that couldn't be done.
On the later 270 and 302 motors, they used a 6 bolt flywheel. It could be chalanging to find a 6 bolt flywheel that is set up for 6 volts. If you are converting the burb to 12 volts, this isn't a problem.
