1950 Chevy Truck F-Body Manifold Modification For LS

It was time to start thinking about the exhaust manifold for the LS 5.3 we dropped into our 1950 Chevy Truck project. The frame is very narrow and we were determined to have a 2 joint steering column. The stock cast iron 5.3 truck manifolds did not come close to working so we borrowed a friends rear drop block hugger headers and those also did not work.

We had stock set of F-Body Firebird manifolds which were steel instead of cast so we tried to fit them in and the passenger side was fine and the drivers side was very close but the O2 sensor and bung were hitting the steering shaft. I figured if I could cut out the O2 bung and weld in a replacement section with a slight indentation it should clear fine. We did just that and we also moved the O2 bung more towards the front and inside of the engine and it clears great now.

While we were welding we cut off all of the emissions provisions and welded plugs in so it looks like they were never there.

Here is the scoop on the drivers side. As you an see when it had the shield and O2 bung in place the single steering rod would not clear.


I drilled out the rivets on the heat shield and tossed it. I them marked the area that would need to be modified to clear the steering shaft. I then took a cut off wheel and and cut the O2 bung out along wiht a little extra metal and test fitted until the steering rod cleared.



We then found a scrap piece of steel and shaped it with a small indentation and welded it in place. We figured out a position where the O2 sensor would clear, drilled a new hole and welded the original bung in place.


We also filled in on of the emotions provisions and ground off the 3 heat shield mounting tabs to give it a cleaner look.


This is the first test fit and it clears the steering rod wiht no problem. It looks a little closer than it really is but it should be fine.


This is what the factory manifold on the passenger side looks like.


This is a picture after we cut off both of the EGR tubes and plug welded them.


This is what it looks like now at first test fit.