[DAVID GAGNARD]

El;

Your on the right track checking the cooling system. The puller fan and shroud could be a problem as I see it in the photo, all the air must past thru the 16" diameter hole where the fan is located, and since the fan itself is shrouded, I don't think you need that real nice aluminum shroud, that could be your problem.....I would remove the aluminum shroud and try it again.....

On my street car as well as my racecar, I use a puller fan similar to yours (slightly larger),but no other shroud other than the one with the fan....At highway speeds, you should have enough airflow to keep the motor cool and as I see it, the shroud would force all the incoming air thru the small 16" diamter fan hole!!!!!!!!!!!!!!!!!!

As to the timing that vettestr aluded to, simple check is to bring # 1 piston to TDC and see where your pointer is in relation to the timing marks on the damper, that would check/eliminate that as a cause...

David