I'm adding an in-line fuel filter before the metal whatchamacallit pictured here. Which line is the feed (from tank), and which is the return?

 

Return is sticking out the side and the feed is the one that is inline with the carb supply. When in doubt just undo the lines and add power to the fuel pump and see where the fuel comes out.

 

Awesome, that's what made most sense to me but I wanted to be sure.

When I put an inline filter in, should I take the brass filter out of the carb inlet, or is having two filters beneficial?

 

I would take it out. That will be another question you won't have to ask if you ever have trouble down the road.

 

Agreed. With a real filter on the fuel line the filter at the carb inlet is kind of a flow restriction at this point and nothing more.

 

This is where I installed an in-line filter. I also made a heat shield and have had no issues with heat. I removed the bronze filter at
carb inlet too. I suggest you replace the 3 way filter, it has a mesh filter inside and most likely full of rust and dirt.

 

Is that the exhaust manifold above the filter in your picture?

I placed my filter right above the oil filter near where the rubber fuel lines turns to the metal one that curves upward toward the ignition coil. I worry that it's too close to the exhaust manifold, as it's only about 2-3 inches away. I thought about fabricating a heat shield, certainly won't hurt.

Where is this three way filter you speak of?

 

It's that whatchamacallit in your photo.