EFE to Manifold Gasket Question

Not been able to find an answer on this site when searching so will post the question.

What does the gasket look like that goes between the EFE butterfly valve and the passenger side exhaust manifold? This would be for a late 70's 350 V8.

Is it a flat gasket or some kind of a tube that fits between the EFE housing and the manifold? It appears that something like that could go between. Not having much luck looking through the parts book. I've attached a couple of stock pics of what the end of my manifold looks like and the corresponding mating surface for the EFE housing.

The truck originally had rusted out headers when I got it, so going back to OEM manifolds and wanting to have a functioning EFE for better warm-up here in Wisconsin.

It's a donut style gasket. 2" or 2.5" listed. https://www.rockauto.com/en/catalog...ust+&+emission,pipe+flange+gasket+/+seal,5836

Should find gasket design below goes against the manifold if the heat riser has a flat surface on the reverse. That style heat riser might be later model than the truck? May also need the spring style header pipe attaching kit. Not totally familiar with earlier trucks so correct me if wrong.


On the header pipe side this style might be what you need.

fast 99 said:

On the header pipe side this style might be what you need.

Click to expand...

I'm thinking the second style is what's needed. I've looked up some of the PN for the different EFE valves and it looks like I've got a later model EFE valve that won't work well with just the flat gasket.

Kilian said:

I'm thinking the second style is what's needed. I've looked up some of the PN for the different EFE valves and it looks like I've got a later model EFE valve that won't work well with just the flat gasket.

Click to expand...

Actually the later style header pipe to heat riser is much better with the spring style connection. The earlier stud/nut type would loosen up over time from frame and motor movement. There are different diameter outlets. You'd be better off taking the samples to a muffler shop or parts store and match everything up rather than ordering on line.