I have a fresh rebuilt Zenith 228 carb (model 11963 that orig came on the GMC 270) that I am ready to set on my stock-setup 261 to replace a junky non-tagged Rochester B. Looks fairly straight forward, but I have a couple of questions:
1. How do I need to set the idle screw? I believe I read in a manual to screw it all the way in, and then back out 1 - 1 1/2 turns. This carb does not have an adjustable main jet.
2. There is a vacuum adaptor, I assume used to connect to the spark advance. However, I am running an HEI distributor from a 250, and the vacuum line from the spark advance is plumbed into a large brass nut connected to the intake manifold. Do I need to plug the carb vacuum inlet with a bolt?
3. My carb doesn't appear to have a bracket for the hand-operated throttle cable. Not even sure how I would find one.
4. Anyone have pictures of a Zenith installed?
To me, this looks like about a 20-minute swap out, but I'm sure there's something I'm missing...
