Pulled the draft tube and it was just about fully clogged up w/60+ yrs of hardened crud.
I decided to go w/a PCV mounted in a freeze out plug installed in the draft tube hole. That mod seems to work very well.
I changed the oil to a thinner grade also (10w30).
Unfortunately after 2 long shakedown cruises, both of which were well over an hr each, a checkout the next morning showed there was new milky crud around the oil fill.
In the cruises the engine temps never got to 180, I'll guesstimate a max of 160-165. The outside temps are cooler.
Looks like the next step is to go w/a 180 thermostat.
Funny, I was really likeing the engine running so cool.....
Dave
