Which engine do I purchase for?
 

After upgrading from the m103 2.6 to the 3.0, which engine should you now purchase for? Ex: the 2.6 plugs were H9DC vs the 3.0 plugs W7DC. The only thing that I swapped out on the 3.0 were the rocker arms, valve springs, and cam shaft as the 3.0 engine I used was from the 103.981 engine that did not have the upgraded rocker arms and cam shaft, so the original lobes were pretty much flattened and deeply grooved.

Interesting that the 2.6 had hotter plugs than the 3.0. There may be other changes to the performance profile baked into the ignition system. Keep an eye on the plugs and gas mileage as the system adapts.

Write it down! so you can look back at it.

I wonder if the thermostats had different opening points too and maybe some of the temperature sensors had different activation points.

-CTH