Thermostat oring question

[Tuc124]

My '69 spider has the internal coolant thermostat at the top of the block. My question: is there one or two Orings required. It looks like there should be one on the bottom and top of the thermostat. I'm finding conflicting information in my searching. When I took the old one out there was only RTV sealant. Thx for helping.

[baltobernie]

Mine has one paper gasket.

[Curly]

Agreed that in theory it should have a rubber ring above and below the thermostat, but two won't fit
I did this job only a couple of weeks ago - The rubber ring goes on top of thermostat and I also used RTV sealant between the head and the the thermostat cover. Sealed up and worked first time
It's also a good idea to place a bit a anti-sieze grease on the 4 thermostat bolt threads before replacing them.

[Tuc124]

Thanks - good info

[vandor]

It needs 2 o-rings. They've always fit for me. These 'o-rings' actually have a rectangular cross-section.

[Curly]

It needs 2 o-rings. They've always fit for me. These 'o-rings' actually have a rectangular cross-section.

That's strange because my workshop manual (Haynes 124 AC/BC/CC Coupes) only shows the one rubber seal.
I had a couple of spares and actually had a go at fitting one above and one below the thermostat; but there was no way the cover would compress them enough to seat the housing against the head face. Maybe the seals you have are thinner than the ones I had.