[ckelly78z]

I read in another post that flat top pistons were standard in 81-83 ZX N/A motors and was wondering what kind of differance they would make in a stock 78 Z with 2.5" exhaust and cold air package. I also wonder if these pistons are affordable brand new and what they would do to my fuel economy???

 

[yo2001]

Somebody said about 15HP. they are affordable. Fuel economy would be good but you got to run 93 oct. gas if you do not want your car to ping. I would do cam with it.

 

[TimZman]

IT WILL RAISE YOUR COMPRESSION TO 10.2 TO 1...AND RAISE YOUR COMPRESSION TO 180 LBS PER CYLINDER, REMEMBER IF YOU DO THIS AND RUN A CAM....YOU'LL NEED TO TWEAK YOUR FUEL MIXTURE..VIA THE MASS AIRFLOW. I JUST DID THAT EXACT THING ON MY 77, BUT I CHANGED TO CARBS FOR THE ADJUSTABLITY, IT IS NAS-TY...BIG IMPROVEMENT FROM STOCK. I RAN THE SECOND STEP CRANE CAM...WITH RETAINERS.