[pheengurs]

one last further update relevant to this thread:

as of this saturday, I also found out why the headers were glowing and why the cooling system was having such a difficult time doing it's job (in addition to previous mistakes!)

spark plugs.

that's right. spark plugs. Napa sold me Champion R17YC instead of the universally recommended AC Delco R44LTS plugs, for higher compression gen1 SBC with vortec heads...

the champions they sold me were not only the wrong heat range but a 1/2" long thread instead of 3/4"

my guess is because the spark was initiating partially inside the threads of the head, the head tried to soak up too much heat and the same for the exhaust side of things...

hence the lean looking condition of the plugs and the center of my block huggers glowing red hot, and coolant boiling all over the bloody place...


Saturday I installed the Delco R44LTS plugs which are 1 heat range colder than stock (?) and on this and many other forums supposed to be one of the plugs choices to use when running betweeen 10.4-12:1 compression.
(I'm currently running at 10.6:1)

The truck did not overheat, the cooling system functioned flawlessly, and I was able to fiddle with timing and mixture without fear for the first time with my new engine...

so if you have the above issues, make sure you are running the correct plug for your application, because it can cause all manner of other unforseeen problems!!!