I have a question regarding the stock Thermostat o-ring that the themostat fits into the o-ring I.D. slot.
The o-ring is twice as thick on one side of the slot as the other.
I confirmed this on 3 different o-ring gaskets.
Should the thicker part of the ring face upwards toward the hood or downwards toward the water pump ?
I would think thick part upwards, placing the thermostat closer to the waterpump so the t-stat could seal into the machined recess in the pump.

 

Your in luck! I happen to have a new 160 stat. The thick part of o-ring is up, thats the way I received it from Hypertech. Danny Mc

 

Thanx for the quick response !