66 Dart GT HT Whatsitgonnabe?
I like bright colors on a motor because I think it makes it easier to see stuff when you're working on it. The red seems like a good choice but I personally might look for the brightest shade of red engine enamel I could find regardless of whether or not it was a Chrysler color. - But I rarely try to keep my cars looking factory original.
As far as painting the heads and water pump a different color than the block... - I like the details to stand out such as pulleys, alternator, belts, power steering pump, etc.. but I usually like the block, water pump, & heads to appear as if they were a single unit. I think that too many different colors may distract the eye from the details that I like to see standing out. JMO