This has always stumped me, can a firing order be changed by just changing the cam? Does the crank also need to be changed? Are a non ho and an ho crank the same except materials? I know big blocks, I have owned, rebuilt and worked on small blocks, but never messed with firing order changes, just cams that goes with the motor.

 

The block and the crank are the same. I've heard they changed to the 351W firing order to put less stress on the crank at higher rpms for longer engine life.

 

It also makes slightly more power... I can't explain why something like less stress and free moving parts. And the 351 order will run a higher rpm

 

Thanks.

 

The HO also uses different pistons in some years. FWIW, the truck cam is a much better grind than the HO.