Stock Exhaust System Questions

[440sixpack]

I have a real nice custom dual exhaust system on my 78 J10. but it was made to fit a chevy engine and I'm converting back to a 360.

My system is 2 1/2 " , I assume the stock system was 2 1/4" ? I have stock manifolds with a 2 1/2" outlet , the book shows both flanges with gaskets or donuts. I assume the donuts were stock? I'm trying to figure out what I need to connect to the stock manifolds basically.

[Tatsadasayago]

If my memory serves me correctly, the drivers side manifold has the tapered donut shaped flange and the passenger side is flat across it's face. The heat riser uses a flat gasket at the manifold and the riser outlet is tapered like the other side.
I don't recall the factory headpipes using a gasket or donut. The headpipe is flared to match the tapered flanges and is held on with a floating 2 bolt collar.
IIRC the SBC flanges were flat.

[440sixpack]

That makes sense, I don't have the heat valve. now I better go measure both sides , I may have to find a heat valve or use a different size flange due to a larger outlet hole. both my manifolds are flat. .

[xGROMx]

What did you do? I have a similar problem. My exhaust system is trashed and past owner tried to fix leaked around the heat riser and destroyed it. Now I just want to eliminate it but don't want to tare it down unroll I have the new pipe prices to bolt and weld together.

Sent from my LG-H900 using Tapatalk