Just bought a 406 SBC with 500 miles on it. Has been sitting for maybe 2 years. Has a Holley Street Avenger 770 CFM Vacuum Secondaries.

A few questions:

What should I do to prime this engine to be started for the first time in two years? Some marvel mystery oil in cylinders? Turn over by hand? Oil change?

Will the Carb need a rebuild? Will the Carb need to be retuned if rebuilt/not rebuilt?

I run a manual transmission. Will the vacuum secondaries prove problematic? If so, why?

Is there any way you can tune a vacuum secondary carb to open up all of its jets at WOT like you can a double pumper?

 

First question: Change oil. After sitting there may be water sitting in the oil pan that has separated. Shouldn't need any special prep other than that.

Second question: The carb will most likely have dried out and will need a rebuild. if rebuilt, retune is in order, if not and the carb runs fine, you will need to retune for whatever application you're using it for anyway. So yes/yes.

Third question: Some folks (namely five7kid) say that mechanical carbs are the only way to go for a stick shift. Though I do not doubt his wisdom in this, I haven't had much problem with mine. It will probably be fine, if it isn't, change it out.

Fourth question: No. Some people put screws in their butterfly arms to achieve a somewhat similar effect but this does NOT work right and will be impossible to tune correctly. Just drop the cash (I know it hurts) and do it right if you plan on going mechanical secondary.

 

Thanks for the info man.

 

I'm here for ya :]