There is no gasket between the engine and transmission.
The torque converter inspection plate does have a dust seal on it.
an exhaust flange gasket, is the gasket,commonly called a donut that is used to seal where the exhaust pipe is bolted to the exhaust manifold
I question the practice why not remove the transmission pan and drain,replace old filter and gasket?? Just makes sense to me
Diagonally
Metallic donut/metal flange type
I would check the Flange gasket. It is the gasket that sits between your exaust manifold and your exaust pipes
It is between the pan and transmission case.
A flange spreader is a device that uses a ratchet, leverage and fulcrum points to spread a bolt together connection. Usually welded pipe to flange, then a seal or gasket, and then another flange, and then welded or threaded pipe carries on. A flange spreader is used to spread the flanges apart to change a gasket or put in a spec blind to blank either side of the connection.
With a tape measure.
just rtv black silicone
It would be best to get a new exhaust gasket.
A flange is the part of the pipe that you can bolt on a blow off valve, O2 Sensor, or other parts like that. The name that you are looking for it the Down Pipe Gasket.
You need to check the transmission gasket between the transmission pan and the body. If it's leaking you have to replace it.