I'm new to the forum and this is my first post. I'm working on my '69 Cutlass with a 5.7. Single exhaust with crossover pipe. Just bought the car before Christmas. I completely rebuilt the engine and got her up and running a couple days ago. Everything is great except for a massive exhaust leak at the manifold flange at the crossover pipe on the driver side. Parts store looked up the part but it's definitely the wrong size gasket/donut. It's way too big. They gave me a felpro 60241. I've searched everywhere and can't seem to find the right size gasket. Does anyone know the correct part number? I eventually want to convert to dual exhaust, but for now just want to hear the rebuilt engine run as it should so I can tune it up. If no one knows the correct part number an exact size would be helpful as well.

Here's a pic of the car since everyone likes to see pics! I did a really crappy photoshop job to give me an idea of what she's gonna look like. I'll probably put on vintage cragars or torq thrusts so don't judge my photoshop wheels!

 

A picture of the leak may help, I am thinking the manifolds on a small block are beveled to match the flare on the pipe and no donuts are used...?

 

As said, no donuts on early manifolds. Personally I would cap it and run duals, factory setup is very restrictive. You may having pitting on the flanges. Clean up and high temp RTV should do the trick.

 

The A-body manifolds are all metal-to-metal. Usually the flare on the crossover pipe rusts, preventing a good seal. If you don't want to run duals, get a new crossover pipe. Use Walker Acousti/Seal P/N 35959 on the sealing surfaces for insurance. This stuff is magic on exhaust leaks. Get it at NAPA, or from Amazon or RockAuto, etc.

 

Thanks guys. That explains why I couldn't find the correct donut... because it doesn't exist. I'll try cleaning up the flanges and give the acousti/seal a shot. If it still leaks on me, I'll lose the crossover and bump dual exhaust to the top of the to-do list.

 

Whether it be dual exhaust or crossover pipe, alignment is important....I have almost always had to bend the pipe a little to get them to seal and then hang properly.

 

if you go dual exhaust w manifolds you simply get the cap for the pass side manifold crossover pipe then run duals to the stock manifolds.

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