My 1976 SS18 with the Onan BG series engine came with a Marvel-Shebler DD series carb. Although a good design it's a bit outdated and I decided to see how easy or hard it would be to convert it to the later style Nikki carbs used on the newer Onan's.
The conversion was basically a direct fit with a few minor twists. The original air cleaner will not work unless you do a lot of modifications. Good news is the later B series, B43, B48 etc air cleaners are a perfect fit with only one minor mod required as you will see shortly.
Main parts required:
New style intake manifold # 541-0428, 146-0495 Nikki Carb, 149-2501 fuel pump or 149-1982.
Pics? You want pics! OK, here they come....
First up the original parts.