The 70 SS had 396 or 454 badges. The 396 was a 402 even thou it said 396 on the car. The 402 just like the 396 came in several HP ranges some good heads some not. Some dogs some not. It was done to meet clean air standards. The engines had to pass a new and 5 year test. The 427 couldn't pass the new test for passenger cars and was gone. The 454 could pass the new test but not the 5 year test and that is why the 454 SS trucks came out to get rid of the 454 engines because the trucks didn't have to meet the clean air standard.