The Scamp may have a 3 inch longer wheel base. If so, her drive shaft wouldn't fit.
One commonly overlooked item in this conversion is a wire. Your 67 has a blue with white tracer that begins at the ignition switch in on position. It powered nothing more than the inst' panel, the voltage regulator, and points ignition.
Look for the same wire in the 74. You'll find it to be a larger gauge wire because it needs to carry more current. It supplies 12 volts to electronic ignition components, alternator field, etc..
This doesn't mean you need to rewire from the ignition switch. That 67 switch has worn contacts inside that wont like the changes anyway.
Find the blue with white coming out of your bulkhead connector, cut it, add a relay, and get the better 12 volts supply through the relay. Plenty of space available on the firewall near the bulkhead connector to add a relay. Branching to the later model components from there pretty simple.
One piece of the 74 engine wiring harness you do not want to use is a white connector at rear of right valve cover. In fact , If the 67 engine harness is in decent condition, I would unwrap and modify it rather than using the 74 engine harness.
