Probably because of my age and lifes experiences I have a little different perspective concerning this subject. I class a car or a truck a hotrod if the engine has been replaced with a much larger engine or the existing engine has really been hopped up for exceptional performance.These cars are normally driven hard and pushed to the limit of performance. They are not setup for full time drag racing and spend the majority of there time on the highway.

The cars & trucks I class as street rods are more cosmetic with fancy body work & paint. Basically running chromed out stock or mildly modified engines. Usually more show than go. Street rods see some street action but spend lots of their time parked in a line of street rods at car shows.

If a guy builds a car with both the above criteria I guess he has built a Hot Street Rod or something to that effect. Also IMO if you own a Musclecar you own a Musclecar. You could possibly call a Musclecar a factory Hotrod.