Originally Posted By: 47Thriftmaster250
Originally Posted By: TonyPa
What was the difference? My nova is a 1978. I seen this on a chart:

LD4 Chevrolet 6 cylinder
The LD4 was a 250-cubic-inch (4.1 L) I6 engine produced strictly in 1978.

What was so different in 78? I know they did the Integral head from 75 and up. Why does this chart say that? Was there something different in 1978 on the 250?


CAFE started mileage requirements for cars in '78. Integral head on truck 250's started in '79, along with CAFE requirements on trucks. The 1978 250 must have had something to do with the first year of CAFE fuel mileage standards, then changed something else on it for '79. Just a guess.


I was wondering, when it said, 78 was one year only. I know I have an integral that they started in 75, but I would think my lower end is all the same. I hope!