Offenhauser intake/Holley 390 thread

I have adapted a BBD carter to the 1 bbl manifold many times and they work very well with only one problem. They tend to generate carburetor ice if too well insulated from the manifold at low ambient temps. Many old irrigation engines had adapters to put a 1BBl on the small 2bbl manifold so I just flipped one of the thin ones over and drilled out the bolt holes deep enough to use a couple of short allen headed bolts that would pull flush.