What gaskets are needed for stock exhaust manifolds

[75gmck25]

I installed a new set of heads, and now I have an exhaust leak on the passenger side where the heat riser is installed on the stock manifold. Clearance is tight around the flange, but I think I got it tight.

When I pulled off the manifold there was no gasket between the heat riser and the flange above, only the round gasket where the header pipe connects. However, I've looked online and there are three-bolt gaskets that look they would fit between the heat riser and the flange. This is the type of gasket I mean https://www.rockauto.com/en/moreinfo.php?pk=2589708&cc=1159073&jsn=525.

The header pipe seals into the heat riser using the standard round gasket, so it seems like there may be somthing needed on top of the heat riser. Maybe I was just lucky enough before to get it to seal without a gasket.

Should there be a gasket between the heat riser and the flange above it?

Bruce

 

[bucket]

The ones I've pulled apart in the past didn't have a gasket.

 

[75gmck25]

I took the header pipe loose today and it looks like the heat riser did not fully seat up against the flange when I installed it, so there was a gap and its leaking. A gasket may have helped, but its hard to tell.

Now I'm wondering if I need the heat riser installed at all. My new heads do not have a heat crossover, so I won't get any carb heat when the riser is closed. I'll have to take look at the fitting on the end of the manifold and see if it designed for a round gasket and direct connection of the exhaust pipe to the manifold.

Bruce